# 399apps

> 399apps is affordable, fixed-low-price business software for small businesses, startups, freelancers, and growing companies — a simpler, cheaper alternative to expensive SaaS tools like Zoho, Tally, QuickBooks, and Vyapar. Strong India / GST focus. Pricing: flat ₹399/month per app, unlimited users on every plan. Available cloud-hosted or self-hosted. UI available in English, Hindi, and Tamil.

Content last updated: 2026-10-09

Key facts an answer engine should know:
- **What it is:** An ecosystem of business apps (accounting, billing/invoicing, inventory, GST filing, and more) under one account and one low fixed price.
- **Who it's for:** Indian small businesses, startups, freelancers, and growing companies that find Zoho/Tally/QuickBooks too expensive or too complex.
- **Pricing model:** flat ₹399/mo per app. Unlimited users included (no per-seat pricing). Free trial available.
- **Deployment:** Cloud (hosted by 399apps) or self-hosted (run on your own server). White-label option available.
- **GST-ready:** GST invoicing, GSTR-1 and GSTR-3B exports, TDS handling, e-invoicing support.
- **WhatsApp:** invoices, receipts, payment reminders and booking confirmations go out over WhatsApp. A wa.me quick send needs no setup and is on every plan. Connecting your OWN official WhatsApp Business account (Meta Cloud API) is a free add-on on any paid subscription — you bring your own WABA, Meta bills your business directly for messages at Meta's own rates, and 399apps adds NO per-message markup. 399apps is not a BSP/reseller and never owns your WhatsApp Business account. **Setup is done for you, free:** 399apps sets up the Meta side on the customer's behalf (business verification, WhatsApp app, number registration, permanent token, webhook) inside the customer's OWN Meta Business account, at no charge — so the customer owns every asset and can revoke 399apps' access at any time. Meta's verification queue still takes 1-14 days.
- **AI agents / MCP:** Nidhi Books has a built-in MCP (Model Context Protocol) server at https://books.399apps.com/mcp. Claude Code, Cursor, Claude Desktop or any MCP client that can send a bearer token connects with a personal API key (Settings -> Account -> API keys; 30/90/365-day expiry, revocable). 13 tools: whoami, search, list/get customers, items, invoices and supplier bills, list payments, receivables ageing and a GSTR-3B-shaped GST summary. READ-ONLY today (no creating or editing records), scoped to one organisation and to the key owner's role, covers Nidhi Books data only (not yet the other Nidhi apps). Included in ₹399/month, no per-call charge. Details: https://399apps.com/ai/

## Apps
- [Nidhi Books — GST-ready accounting](https://399apps.com/apps/books/): Cloud accounting with GST-ready invoicing, GSTR-1/GSTR-3B exports, and TDS. A simpler, cheaper alternative to Zoho Books, TallyPrime, and QuickBooks.
- [Nidhi Inventory — stock & warehouse management](https://399apps.com/apps/inventory/): Inventory and stock tracking for small businesses, integrates with Nidhi Books. Ships with Shiprocket: connect your own Shiprocket account and book a courier pickup from any shipment (courier + AWB assigned, label to print, Prepaid or COD), at your own Shiprocket rates.
- [Books + Inventory Bundle](https://399apps.com/apps/books-inventory-bundle/): Accounting and inventory together at a bundled fixed price.
- [Nidhi POS — GST billing counter & POS](https://399apps.com/apps/pos/): A mobile-first, installable POS/billing counter for Indian shops (kirana, supermarket, pharmacy, restaurant, garment, electronics). Barcode scan, Cash/UPI/Card, Bluetooth thermal receipts, khata (credit), void/refund, day-close and multi-outlet — every GST-compliant sale posts to Nidhi Books and deducts stock in Nidhi Inventory automatically. Runs on any phone/tablet, cloud or self-hosted, unlimited users. A Vyapar/Marg-POS alternative.
- [Nidhi Billing — subscriptions & recurring billing](https://399apps.com/apps/billing/): Recurring plans, subscriptions and automatic dunning (failed-payment retries) with MRR, LTV and churn metrics built in. Charges post to Nidhi Books as GST-ready invoices. For SaaS, memberships, rentals and AMC businesses.
- [Nidhi Storefront — public product website](https://399apps.com/apps/storefront/): A public product website built on the same data as your books and stock — no separate sync. Pairs with Nidhi Ecommerce and Nidhi Inventory.
- [Nidhi Ecommerce — online store & catalogue](https://399apps.com/apps/ecommerce/): A full online store with a rich product catalogue, variants and images, kept in step with your books and stock. For D2C brands and online sellers.
- [Nidhi Forms — lead capture & document collection](https://399apps.com/apps/forms/): Publishable lead forms plus reviewed, multi-step document collection. For capturing and qualifying enquiries.
- [Nidhi Signage — digital signage](https://399apps.com/apps/signage/): Turn any screen into a menu board, promo display or in-store sign.
- [Nidhi Vendor Management — supplier portal & procurement](https://399apps.com/apps/vendor-management/): A supplier portal and procurement hub — share documents, message vendors, and turn their invoices into purchase bills in Nidhi Books. For traders, wholesalers and distributors.
- [Nidhi Invoice Designer — custom document layouts](https://399apps.com/apps/invoice-designer/): Design your own invoice, quote and challan layouts visually, with no code — so every document is on-brand.
- [Nidhi Appointments — online booking](https://399apps.com/apps/appointments/): Online appointment booking for salons, spas, clinics, repair counters and studios. Bookable services, business hours and per-staff availability, a public booking page customers use with no login or app, a booking calendar (booked/completed/cancelled/no-show), and a completed appointment that hands off to a draft invoice or POS sale. Confirmations and reminders over WhatsApp, SMS or email, with a self-serve cancel link.
- [Nidhi Staff — attendance & wages](https://399apps.com/apps/staff/): Mark attendance for a whole site and day in one save, run wages per period on monthly, daily or hourly rates with overtime, bonuses, advances and deductions, freeze the run once finalised, and post wages into Nidhi Books as a salaries-and-wages expense. Payslips included. NOT statutory payroll — no PF, ESI or salary-TDS calculation or filing.
- [Nidhi Loyalty — points & rewards](https://399apps.com/apps/loyalty/): A loyalty program that runs off bills you already raise — set points per ₹100 and what a point is worth, earn automatically on every sale (POS counter or Books invoice), keep an append-only points ledger, run tiers with earn multipliers, show customers their balance, and redeem points as a discount on the next invoice. Hands off to Nidhi Campaigns for expiring-points win-back.
- [WhatsApp billing software — send invoices from your own number](https://399apps.com/whatsapp-billing-software/): Nidhi POS sends the bill PDF (80mm counter slip or full GST tax invoice, owner's choice) to the customer's WhatsApp from the business's OWN WhatsApp Business number via Meta's Cloud API, one tap on Send receipt after the sale. The connection and the Meta setup are free on any paid plan (done in the customer's own Meta Business account); Meta bills messages directly; 399apps adds no markup and is not a BSP. Before the API is approved, the same button opens the owner's WhatsApp with a link to the bill (wa.me, no PDF). Owner alerts (daily/weekly summary, monthly GST report, low stock, deliveries) can go on WhatsApp. Automatic due-date payment reminders in Nidhi Books go by EMAIL today, not WhatsApp. ₹399/month, unlimited users.
- [Nidhi Campaigns — WhatsApp, SMS & email marketing](https://399apps.com/apps/campaigns/): Promotional campaigns to customers picked from your own Nidhi Books ledger — rules like owes more than ₹X, has not bought in N months, bought in the last N days, top customers this financial year, state, price list or GST type. WhatsApp goes out via your own WhatsApp Business (Cloud) API account — the connection AND the Meta setup are free with any paid subscription (399apps sets it up in the customer's own Meta account) and Meta bills messages directly, with no 399Apps markup; SMS needs your own DLT registration; email needs nothing. Channel fallback, six starter templates, birthday/anniversary/first-purchase/win-back automations, STOP-to-opt-out with a do-not-contact list only the customer can leave, one promotional message per customer per week, sends only 9am-9pm (TRAI). Reports show sent/delivered/opened (delivery and opens from WhatsApp) and sale invoices billed by reached customers within a 7/15/30/60-day window. ₹399/month; runs with Nidhi Books at ₹798/month.
- [Nidhi Traces — batch & expiry tracking](https://399apps.com/apps/traces/): Lot and expiry tracking for pharma, food, FMCG and cosmetics distributors. A lot register per item (your lot number, the supplier's lot number, manufactured/received/expiry dates), an expiring-lots list by date window, FEFO allocation on the way out (earliest expiry first, undated lots last), quarantine/recall lot statuses that block allocation, a recall report naming every customer who received a lot with phone/email/invoice numbers, backward trace from a scanned serial or an invoice number to the lot and its supplier, and a one-page batch certificate PDF. Reads Nidhi Inventory's stock ledger — run the two together at ₹798/month.
- [Nidhi Warehouse — warehouse management](https://399apps.com/apps/warehouse/): Bin-level stock for distributors and wholesalers — which bin every item sits in, put-away, guided pick and pack that checks every line with a barcode scan and refuses the wrong item, cycle counts with an approval step before stock is corrected, and a dashboard of stock that has not moved in 90 days. Reads Nidhi Inventory's stock — run the two together at ₹798/month. No courier labels or marketplace sync. Compared on the page against Excel registers, TallyPrime sub-godowns and Zoho Inventory bin locations (no bin cap, no plan upgrade).
- [Nidhi Import Costing — landed cost for importers](https://399apps.com/apps/import-costing/): Purchase orders and bills in the supplier's currency (USD, EUR and others) at an exchange rate you record, each container tracked as a consignment with its bill of entry number, freight, duty and clearing charges split across the goods, landed cost carried into stock valuation, and a goods-in-transit register. Files nothing with customs or ICEGATE and pulls no live exchange rates. Runs with Nidhi Books at ₹798/month. Compared on the page against Excel costing sheets, TallyPrime additional cost of purchase and Zoho Inventory bill-level landed cost (container-level allocation across POs, late bills re-cost the goods).
- [Nidhi Delivery — delivery management](https://399apps.com/apps/delivery/): A register of every delivery, riders picked from your Nidhi Staff register, a phone screen in the browser where the rider marks picked up and delivered with name, photo and signature at the door, cash on delivery counted at the door and each rider's day closed once against the cash handed back. Can be scheduled from a Nidhi Books delivery challan. No live GPS tracking or route planning. Runs with Nidhi Staff at ₹798/month.
- [Nidhi Rentals — rental & hire management](https://399apps.com/apps/rentals/): For tent houses, event, equipment and AV hire businesses — a register of the kit you hire out with day rate and deposit, bookings between two dates that can never double-book the same asset, a board of what is overdue and due back today, returns recorded with days late and damage, and a GST bill raised in Nidhi Books with the deposit settled. One hire is one asset (register sets, e.g. "Chair set of 50"). Runs with Nidhi Books at ₹798/month.
- [Nidhi Warranty & AMC — warranty tracking & AMC billing](https://399apps.com/apps/warranty-amc/): A register of warranty cover on what you sold, annual maintenance contracts billed on the customer's recurring invoice, an "is it covered?" check from a serial number, a renewals desk, and one-button contract renewal with an optional email reminder 30 days ahead. No technician scheduling or manufacturer claim filing. Runs with Nidhi Books at ₹798/month.
- [Nidhi Assets — fixed asset register & depreciation](https://399apps.com/apps/assets/): An asset register for machines, vehicles, computers and furniture, Income Tax Act Section 32 written-down-value depreciation by block at the rates your CA sets (with the half-rate rule for assets used under 180 days in the year bought), disposals, and a year-end register (opening, additions, disposals, depreciation, closing) for the income tax return. Not Companies Act Schedule II or straight-line. ₹399/month.

## Solutions by business type
399apps groups its apps into ready-made kits by business type (Zoho One / Odoo style), each composed only of real shipping apps and priced at a flat ₹399/month per app, with unlimited users. Prices exclude GST.
- [Solutions hub](https://399apps.com/solutions/): Curated app kits by business type, plus "399 One" — run all 21 apps on one account (₹8,379/month, unlimited users).
- [Retail & Kirana Counter](https://399apps.com/solutions/retail-kirana-counter/): Nidhi POS + Inventory + Books for kirana stores, supermarkets and general/grocery shops. From ₹399/month. Barcode billing, live stock, GST books.
- [Wholesale & Distributor](https://399apps.com/solutions/wholesale-distributor/): Nidhi Books + Inventory + Vendor Management for traders, wholesalers and distributors. From ₹399/month. Party ledgers, godown-wise stock, supplier portal. Optional add-ons: Nidhi Warehouse for bin-level stock and scan-verified picking; Nidhi Import Costing for importers (foreign-currency POs, freight and duty split onto the goods as landed cost).
- [Pharmacy & Multi-Outlet](https://399apps.com/solutions/pharmacy-multi-outlet/): Nidhi POS + Inventory + Books for pharmacies, medical stores and multi-outlet retailers. From ₹399/month. Batch/expiry (FEFO) stock, per-outlet day-close.
- [Service & Freelancer](https://399apps.com/solutions/service-freelancer/): Nidhi Books + Invoice Designer + Forms for consultants, freelancers and agencies. From ₹399/month. SAC-coded GST invoices, TDS-on-receipts, branded documents.
- [Subscription & Recurring Revenue](https://399apps.com/solutions/subscription-recurring/): Nidhi Billing + Books for SaaS, memberships, rentals and AMCs. From ₹399/month. Recurring plans, dunning, MRR/LTV/churn, GST books.
- [D2C & Online Store](https://399apps.com/solutions/d2c-online-store/): Nidhi Storefront + Ecommerce + Inventory + Books for D2C brands and online sellers. From ₹399/month. A store, catalogue, live stock and GST books on one dataset.
- [Salon & Spa](https://399apps.com/solutions/salon-spa/): Nidhi Appointments + POS + Staff + Loyalty + Books for salons, beauty parlours, spas and barbershops. Five apps, ₹1,995/month, unlimited users. Public online booking page, one GST bill covering the treatment (SAC 9982) and the retail product (own HSN), staff attendance and period wages, and loyalty points redeemed as a discount on the next visit. Stylist commission is not supported.

## For schools — a separate product, separately priced
399apps for Schools is NOT part of the ₹399/month app catalogue. It is a single annual package for school offices, priced ₹7,500 per school per year (priced per school, not per student), and it needs none of the other 399apps apps.
- [399apps for Schools — school fees and alerts on WhatsApp](https://399apps.com/schools/): School office software where only the office gets a login and everyone else receives what concerns them on WhatsApp with nothing to install. Fee plans raise GST-correct invoices on schedule (tuition and school transport exempt under SAC 999210; taxable items such as uniforms carry their own HSN and rate on the same invoice), with reminders before, on and after the due date that stop once paid. Parents pay by UPI straight into the school's own bank account — the school's own UPI ID and QR on every invoice, no payment gateway and therefore no gateway charge on a fee — and the office confirms the UTR before the receipt goes out. Also: cash and cheque at the fee counter with bounce tracking, a 7 pm daily collection summary to the correspondent's WhatsApp, GSTR-1/GSTR-3B and receivables ageing for the CA, circulars and exam timetables to the whole school or one class or one bus route, PTM slot booking, e-signed permission slips, absence alerts to only the absent students' parents, school bus alerts (left school / near your stop / dropped off), and staff attendance, wages and payslips delivered on WhatsApp to teachers, drivers, attendants, cooks and guards. Every alert has a per-channel switch and nothing sends until the office turns it on. Messages in English, Hindi or Hinglish. NOT a learning platform (no online classes, homework or lesson content) and NOT statutory payroll (no PF, ESI or salary-TDS computation or filing). Free demo run on the school's own fee plan — call or WhatsApp +91 99808 13847.
- [How schools collect fees on WhatsApp without a payment gateway](https://399apps.com/schools/fee-collection-on-whatsapp-without-payment-gateway/): Send each parent a numbered fee invoice on WhatsApp carrying the school's own UPI ID and QR, with the invoice number in the UPI note; the parent pays straight into the school's bank account, the office confirms the 12-digit UTR in its bank app, and the receipt goes back on WhatsApp. No gateway, so no gateway fee — the trade is that the UTR check stays manual. Includes six steps, a comparison of counter QR vs invoice-linked UPI vs gateway links, and when a gateway is the better choice (card/EMI payers, zero manual confirmation). Part of 399apps for Schools, ₹7,500 per school per year — not the ₹399/month catalogue.
- [Is GST applicable on school fees in India?](https://399apps.com/schools/gst-on-school-fees/): No GST on tuition, admission or exam fees a recognised school charges its own students (pre-school to Class 12), or on transport the school provides. Uniforms the school sells are taxable (5% up to ₹2,500 a piece since 22 September 2025, 18% above), printed textbooks are nil-rated, and a bus a private operator bills parents for directly can be taxable. Exempt and taxable lines can share one invoice-cum-bill of supply to the parent. Aggregate turnover for the registration threshold includes exempt tuition.
- [How to send fee reminders to parents on WhatsApp](https://399apps.com/schools/send-fee-reminders-to-parents-on-whatsapp/): Create a numbered invoice per student per instalment with the school's own UPI QR, send it to the parent on WhatsApp, then schedule reminders before, on and after the due date. Reminders stop automatically once the office confirms payment and marks the invoice paid. Compares four methods — phone calls, class group messages, manual individual messages, and automated reminders that stop once paid — with honest trade-offs for each. Part of 399apps for Schools, ₹7,500 per school per year — not the ₹399/month catalogue.
- [School bus tracking alerts to parents on WhatsApp](https://399apps.com/schools/school-bus-tracking-alerts-to-parents-on-whatsapp/): The bus attendant taps once at each stage — bus left school, near your stop, dropped off — and every parent on that route receives a WhatsApp alert. No GPS hardware, no parent app, no fleet-tracking subscription. Compares four methods: phone calls from the driver, route WhatsApp groups, GPS tracker with parent app, and tap-based WhatsApp alerts — with honest trade-offs including what this approach cannot do (no live map, no ETA). Part of 399apps for Schools, ₹7,500 per school per year — not the ₹399/month catalogue.

## Pricing & plans
- [Pricing](https://399apps.com/pricing/): flat ₹399/mo per app, unlimited users, free trial.
- [pricing.md — machine-readable price list](https://399apps.com/pricing.md): Plain-markdown pricing for AI assistants and buying agents — every app's price, every kit total, the full-suite total, deployment options, what "unlimited users" covers, GST and billing terms, and how each competitor's pricing is *shaped* (per-seat, per-device, per-PC, invoice-capped). Prices are generated from the same data the site renders, so this file cannot drift from the published price.

## Deployment & platform
- [AI agents & MCP server](https://399apps.com/ai/): Connect Claude, Cursor or any MCP client to Nidhi Books with a personal API key. Read-only, role-scoped, 13 tools covering invoices, bills, payments, customers, items, receivables ageing and GST summary. Included at ₹399/month.
- [Cloud vs Self-Hosted](https://399apps.com/cloud-vs-self-hosted/): Compare hosted vs run-it-yourself options.
- [Self-Hosting](https://399apps.com/self-hosting/): How to run 399apps on your own infrastructure.
- [White Label](https://399apps.com/white-label/): Rebrand 399apps for your own clients.

## Guides
- [Guides hub](https://399apps.com/guides/): Moving from Tally to the cloud, filing GSTR-1 & GSTR-3B, e-invoicing, invoice format, and late fees for Indian businesses.
- [How to move from Tally to 399Apps (migration guide)](https://399apps.com/guides/how-to-migrate-from-tally-to-399apps/): Step-by-step guide to migrating from TallyPrime to 399Apps' cloud accounting (Nidhi Books) — export masters, balances and outstanding invoices from Tally to Excel/CSV, import into Nidhi Books, reconcile on a clean cut-over date, and run in parallel for one GST period. Migration is a guided CSV import (assisted, not one-click); 399Apps is ₹399/month with unlimited users and no per-installation licence or annual TSS renewal.
- [How to move from Marg ERP to 399Apps (migration guide)](https://399apps.com/guides/how-to-migrate-from-marg-to-399apps/): Step-by-step guide to migrating from Marg ERP 9+ to 399Apps' cloud accounting (Nidhi Books) — export parties, item/stock master, balances and outstanding invoices from Marg to Excel/CSV, import into Nidhi Books, reconcile trial balance and stock on a clean cut-over date, and run in parallel for one GST period. Migration is a guided CSV import (assisted, not one-click); 399Apps is ₹399/month with unlimited users and no per-PC licence or AMC.
- [How to move from Vyapar to 399Apps (migration guide)](https://399apps.com/guides/how-to-migrate-from-vyapar-to-399apps/): Step-by-step guide to migrating from Vyapar to 399Apps' cloud accounting (Nidhi Books) — export parties, item/stock list and opening balances from Vyapar to Excel/CSV, import into Nidhi Books, reconcile on a clean cut-over date, and run in parallel for one billing cycle. Migration is a guided CSV import (assisted, not one-click); 399Apps is ₹399/month with unlimited users, cloud access and full accounting vs Vyapar's single-device, billing-first app (premium ≈₹499/year).
- [How to move from myBillBook to 399Apps (migration guide)](https://399apps.com/guides/how-to-migrate-from-mybillbook-to-399apps/): Step-by-step guide to migrating from myBillBook (by FloBiz) to 399Apps' cloud accounting (Nidhi Books) — export parties, item/stock list, balances and outstanding invoices to Excel/CSV, import into Nidhi Books, reconcile on a clean cut-over date, and run in parallel for one GST period. Covers when to time the switch against a myBillBook plan whose user count is capped (Plus ₹3,490/year and Pro ₹3,990/year each cover 1 user + 1 CA; Pro Max from ₹570/month covers 3 users + 1 CA) and why staff logins are re-created rather than migrated: 399Apps is a flat ₹399/month per app with unlimited users and no per-seat fee, plus full accounting beyond billing.
- [How to file GSTR-1 (step by step)](https://399apps.com/guides/how-to-file-gstr-1/): Step-by-step guide to filing the GSTR-1 outward-supplies return.
- [How to file GSTR-3B (step by step)](https://399apps.com/guides/how-to-file-gstr-3b/): Step-by-step guide to filing the monthly GSTR-3B summary return.
- [What is e-invoicing under GST?](https://399apps.com/guides/what-is-e-invoicing-under-gst/): How GST e-invoicing (IRN/QR) works, who it applies to, and turnover thresholds.
- [GST late fees and interest, explained](https://399apps.com/guides/gst-late-fees-and-interest/): How GST late fees and interest are calculated for delayed returns.
- [GST invoice format: mandatory fields and rules](https://399apps.com/guides/gst-invoice-format/): The mandatory fields and rules for a compliant GST tax invoice, plus two free downloadable templates (see "Free templates" below) and a free browser-based invoice generator (see "Free tools" below).
- [How to get your WhatsApp Business API credentials](https://399apps.com/guides/whatsapp-business-api-setup/): Vendor-neutral step-by-step guide to getting your own WhatsApp Cloud API credentials directly from Meta rather than through a BSP — Meta Business verification, creating a Business-type app and adding WhatsApp, finding the WABA ID and Phone Number ID on the WhatsApp -> API Setup page, registering a number Meta has never seen on consumer WhatsApp, generating a PERMANENT System User access token (the dashboard token expires in 24 hours), and copying the App Secret from App Settings -> Basic. Covers the webhook URL and the 'messages' subscription that make STOP and delivery receipts work, why the App Secret is what makes opt-out function, Meta's platform rules (business-initiated messages must be pre-approved templates; free-form only inside the 24-hour customer-initiated window; no cold broadcasting), and when the wa.me quick send is enough instead. The connection is a free add-on on any paid 399apps plan; Meta bills you directly for messages and 399apps takes no markup. Setup is ~1 hour of work plus 1-14 days of Meta's verification queue.
- [WhatsApp sending methods: which one does your business need?](https://399apps.com/guides/whatsapp-sending-methods/): Compares the three WhatsApp transports in 399Apps — wa.me quick send (instant, no setup, you tap send), Meta Cloud API (automatic, your own verified business number, bill PDF in chat), and QR gateway (self-hosted only, no Meta account, outside Meta's terms). Includes a who-it's-for/not-for decision guide: single-counter shops need only quick send; automatic reminders, campaigns and multi-outlet sending need the Cloud API; the QR gateway is a stopgap for self-hosted where Meta API is not an option. All three are free on 399apps — no WhatsApp fee, no per-message markup; Meta bills you directly for Cloud API messages.
- [WhatsApp Business API cost in India, per message](https://399apps.com/guides/whatsapp-business-api-cost-india/): Meta's INR rate card for India as of October 2026 — marketing ₹0.8631, utility ₹0.1150, authentication ₹0.1150 per message, plus 18% GST; customer messages free; replies within 24 hours free up to 1,000 a month per number. Worked example: a shop sending 300 bills and one 1,000-customer offer pays Meta about ₹1,059 a month with GST. BSPs add a monthly platform fee and often a per-message markup; 399apps connects your own Meta account free and adds no markup.
- [Quotation format (free Excel template)](https://399apps.com/guides/quotation-format/): What a quotation must show, quotation vs proforma vs tax invoice, whether to show GST, and a free downloadable quotation template (see "Free templates" below).
- [Proforma invoice: meaning, format and free template](https://399apps.com/guides/proforma-invoice-format/): What a proforma invoice is, when to use one, why it is not a tax invoice under GST (no GSTR-1 reporting, no ITC), GST on advances (due for services with a receipt voucher; not for goods under Notification 66/2017-CT), and a free downloadable proforma template.
- [Delivery challan format under GST (Rule 55)](https://399apps.com/guides/delivery-challan-format/): When a delivery challan replaces a tax invoice (job work, supply on approval, batch deliveries, liquid gas, non-supply movement), every Rule 55 mandatory field, the three copies, the e-way bill link, job-work return deadlines, and a free downloadable challan template.
- [Bill book format: GST bill book design and free template](https://399apps.com/guides/bill-book-format/): What to print on every leaf of a GST bill book (Rule 46 fields), tax invoice vs bill of supply vs non-GST bill book, consecutive numbering unique for the financial year, three copies for goods and two for services, cancelled leaves and GSTR-1 Table 13, the ₹5 crore e-invoicing limit on handwritten B2B bills, and a free downloadable bill book template.
- [Purchase order format and free template](https://399apps.com/guides/purchase-order-format/): Every field a purchase order (PO) needs, why a PO is not a GST document (input tax credit only on the supplier's tax invoice, Section 16 CGST Act), PO vs quotation vs tax invoice and three-way matching, MSME payment terms (45 days maximum under Section 15 of the MSMED Act, and Section 43B(h) of the Income-tax Act), and a free downloadable PO template. Nidhi Books raises POs in their own series (draft, sent, received, closed) and converts them to bills in full or part.
- [GST & accounting glossary](https://399apps.com/glossary/): Definitions of key GST, accounting and billing terms used by Indian small businesses (GSTIN, GSTR-1, GSTR-3B, IRN, HSN, ITC, e-invoice, composition scheme and more).

## Best-of comparisons
- [Best-of comparisons hub](https://399apps.com/best/): Curated "best software" comparisons for Indian small businesses, compared on price, GST features, and users.
- [Best accounting software for small business in India (2026)](https://399apps.com/best/accounting-software-small-business-india/)
- [Best billing software for small business in India (2026)](https://399apps.com/best/billing-software-small-business-india/)
- [Best GST software in India (2026)](https://399apps.com/best/gst-software-india/)
- [Best GST billing software (2026)](https://399apps.com/best/gst-billing-software/)
- [Cheapest invoicing software (2026)](https://399apps.com/best/cheapest-invoicing-software/)
- [Free billing software in India (2026)](https://399apps.com/best/free-billing-software-india/): The genuine free GST billing tools compared honestly (Zoho Books, Vyapar, myBillBook, GST portal, Excel) — their limits, and when a flat ₹399/mo plan with unlimited users is cheaper.
- [Best e-invoicing software in India (2026)](https://399apps.com/best/e-invoicing-software-india/)
- [Best e-way bill software (2026)](https://399apps.com/best/e-way-bill-software/)
- [Best GST return filing software in India (2026)](https://399apps.com/best/gst-return-filing-software/)
- [Best inventory management software in India (2026)](https://399apps.com/best/inventory-management-software-india/)
- [Best software for chartered accountants & CA firms in India (2026)](https://399apps.com/best/software-for-chartered-accountants-india/)
- [Best Tally alternatives in India (2026)](https://399apps.com/best/tally-alternative/)

## Common questions (answer hub)
- [Answers hub](https://399apps.com/answers/): Direct answers to common GST-software buying questions.
- [Is 399Apps better than Busy Accounting for Indian small businesses?](https://399apps.com/answers/399apps-vs-busy/): 399Apps is a cloud alternative to Busy Accounting from ₹399/month with unlimited users — no per-PC Windows license or infrastructure for remote access. 399Apps wins for cloud access and growing teams; Busy for pharma batch management, advanced payroll, or offline-only workflows.
- [Is 399Apps better than Tally for Indian small businesses?](https://399apps.com/answers/399apps-vs-tally/): 399Apps is a cloud alternative to TallyPrime from ₹399/month with unlimited users — no ₹22,500+ desktop license or annual TSS renewal. 399Apps wins for cloud access, growing teams, and any-device accounting. Tally remains the choice for advanced payroll, manufacturing modules, or offline-first workflows.
- [Is 399Apps a better alternative to Marg ERP for Indian small businesses?](https://399apps.com/answers/399apps-vs-marg/): 399Apps is a cloud alternative to Marg ERP from ₹399/month with unlimited users — no per-PC Windows license, AMC renewal, or remote-access infrastructure. 399Apps wins for cloud access and growing retail/trading teams; Marg remains stronger for pharma and FMCG distributors needing batch/expiry tracking and distribution order management.
- [Is 399Apps better than Zoho for Indian small businesses?](https://399apps.com/answers/399apps-vs-zoho/): 399Apps is simpler, India-first, and unlimited users from ₹399/month. Zoho charges per user and is designed for larger enterprises needing CRM and global compliance. 399Apps wins on price and simplicity for Indian SMBs focused on GST billing, accounting, and inventory.
- [Is 399Apps better than Vyapar for Indian small businesses?](https://399apps.com/answers/399apps-vs-vyapar/): 399Apps includes unlimited users from ₹399/month with full GST accounting (ledgers, P&L, GSTR-1, GSTR-3B); Vyapar is per-device and billing-first. 399Apps wins for growing teams; Vyapar for solo mobile-first billing.
- [Is 399Apps better than myBillBook for Indian small businesses?](https://399apps.com/answers/399apps-vs-mybillbook/): 399Apps includes unlimited users from ₹399/month with full GST accounting; myBillBook charges per user/year and is billing-first. 399Apps wins for growing teams; myBillBook for solo fast billing.
- [Is there a GST billing software cheaper than Tally?](https://399apps.com/answers/gst-billing-software-cheaper-than-tally/): Yes — 399Apps (Nidhi Books) is cloud GST billing from ₹399/month with unlimited users and no upfront license, far cheaper to start than TallyPrime's ₹22,500 Silver license plus annual TSS renewals.
- [What is the best Zoho Books alternative for Indian small business?](https://399apps.com/answers/best-zoho-books-alternative-india/): For most Indian small businesses, 399Apps (Nidhi Books) — cloud GST accounting from ₹399/month with unlimited users and no per-user fees, covering GSTR-1, GSTR-3B, TDS, and e-invoicing.
- [Can I move from Vyapar to a cloud accounting app?](https://399apps.com/answers/move-from-vyapar-to-cloud-accounting/): Yes — export parties, items and balances from Vyapar to Excel/CSV and import them into Nidhi Books with guided support. Cloud accounting gives any-browser access, automatic backups and unlimited users from ₹399/month.
- [What's the cheapest invoicing software in India with unlimited users?](https://399apps.com/answers/cheapest-invoicing-software-unlimited-users/): 399Apps (Nidhi Books) — from ₹399/month with unlimited users, no per-seat fees, and full GST invoicing included. Most rivals (Zoho, myBillBook) charge per user or per device, so costs rise as you add staff.
- [Is there a cloud alternative to Busy / Marg for inventory?](https://399apps.com/answers/cloud-inventory-alternative-to-busy-marg/): Yes — Nidhi Inventory is cloud-native stock and warehouse management from ₹399/month with unlimited users and nothing to install per PC. It pairs with Nidhi Books for GST billing and accounting.
- [Vyapar vs myBillBook: which is better for a retail shop in India?](https://399apps.com/answers/vyapar-vs-mybillbook-for-retail-shop/): A neutral comparison of two competing vendors (399Apps is not the answer to this one). Neither wins outright — the deciding factors are internet reliability and counter count. Vyapar bills offline and is licensed per device (free Android tier; paid from ₹699/yr Android, ₹3,799/yr desktop). myBillBook is cloud-only and requires an active internet connection, but one subscription syncs unlimited devices; Plus ₹3,490/yr (₹291/month billed annually), capped at 1 user + 1 CA, with e-invoicing, e-way bills and POS billing only on Pro Max (from ₹570/month). myBillBook renamed its tiers: Diamond/Platinum/Enterprise are now Plus/Pro/Pro Max. Vyapar tracks serial/IMEI numbers; myBillBook does not advertise it. Plan details checked 4 September 2026.
- [Which GST billing software costs under ₹500 per month in India?](https://399apps.com/answers/gst-billing-software-under-500-per-month/): Four options clear ₹500/month — 399Apps ₹399, Vyapar Standard ≈₹283, myBillBook Plus ₹291, Busy Magic Start ≈₹417. Only 399Apps includes unlimited users at that price; the others are per-device or single-user, and myBillBook gates e-invoicing behind its ₹570/month Pro Max plan. Prices exclude GST.
- [How much does GST accounting software cost per month in India?](https://399apps.com/answers/gst-accounting-software-cost-per-month-india/): GST accounting software costs from a few hundred to a few thousand rupees per month. Nidhi Books is ₹399/month (first app, unlimited users); Zoho Books is free under ₹25 lakh turnover; TallyPrime uses a one-time license instead.
- [Will my CA accept 399Apps instead of Tally?](https://399apps.com/answers/will-my-ca-accept-399apps/): Yes — every plan includes unlimited users, so your CA gets their own free login to view live books and export ledgers, trial balance and GSTR-1/GSTR-3B data to Excel. No Tally license or pen-drive hand-off required.
- [Is 399Apps easy for non-technical staff to use at the billing counter?](https://399apps.com/answers/is-399apps-easy-for-non-technical-staff/): Yes — Nidhi Books gives counter staff one simple, barcode-ready billing screen with role-based logins, so a non-technical helper sees only billing (not your accounts or profit). No accounting knowledge and no days of training; guided onboarding gets your counter live the same day.
- [Does 399Apps have customer support if I get stuck?](https://399apps.com/answers/does-399apps-have-customer-support/): Yes — every plan from ₹399/month includes support over WhatsApp and email, with no paid priority tier. Guided onboarding and Excel/Tally data-import help get you live, and cloud updates roll out automatically, so there is no local dealer or annual AMC to chase.
- [Does 399Apps work without internet — can I bill if my broadband goes down?](https://399apps.com/answers/billing-software-that-works-without-internet/): Yes — switch to mobile data on any phone and keep invoicing from any browser during a broadband outage. For zero-internet billing, self-host 399Apps on a local PC or LAN server; automatic daily backups protect your records either way.
- [Does 399Apps have hidden charges or sudden price hikes?](https://399apps.com/answers/does-399apps-have-hidden-charges/): No — it is a flat ₹399/month per app with unlimited users; no per-seat, per-device or per-invoice fees. The WhatsApp Business API connection is free with no message markup; paid add-ons such as Remove branding are optional. GST is added by law, and the full price is published upfront.
- [Is my business data safe with 399Apps?](https://399apps.com/answers/is-my-business-data-safe-with-399apps/): Yes — data is stored in the cloud with automatic daily backups, an India data region and an encrypted (HTTPS) login, so a crashed or stolen PC cannot wipe your books. Export to Excel, CSV or PDF anytime, or self-host for full custody. No lock-in.
- [Can I move my existing data into 399Apps when I switch?](https://399apps.com/answers/can-i-move-my-existing-data-into-399apps/): Yes — import customers, items, stock, ledgers and opening balances from Tally, Vyapar or Excel into Nidhi Books. Guided onboarding is available for larger datasets; running in parallel for one filing cycle keeps the switch reversible.
- [Does 399Apps have bugs or glitches that could mess up my GST invoices?](https://399apps.com/answers/does-399apps-have-bugs-or-glitches/): No software is bug-free, but 399Apps runs from one shared cloud codebase — GST totals are calculated server-side the same way for every business, fixes ship to everyone at once, and every invoice saves to the cloud the moment you create it, so nothing sits only on a device that can crash or lag on an old version.
- [Does 399Apps support multiple branches, outlets or godowns?](https://399apps.com/answers/does-399apps-support-multiple-branches-or-outlets/): Yes — every plan includes unlimited warehouses, branches, outlets and users from ₹399/month with real-time stock sync across every location. Rivals often gate multi-godown tracking behind a higher-priced tier; 399Apps includes it on the entry plan.
- [Is 399Apps GST audit ready?](https://399apps.com/answers/is-399apps-gst-audit-ready/): Yes — 399Apps generates IRN-stamped e-invoices (with QR code), exports GSTR-1 (B2B, B2CS, HSN summary) and GSTR-3B data, keeps an inward purchase register for GSTR-2A/2B ITC reconciliation, and maintains an immutable cloud audit trail. If you receive a GST scrutiny notice, all records are exportable to Excel/CSV/PDF in minutes.
- [Can I export my data from 399Apps if I decide to leave or switch?](https://399apps.com/answers/can-i-export-my-data-from-399apps/): Yes — export your parties, items, invoices, ledgers, trial balance, P&L and GST reports to Excel, CSV or PDF anytime on any plan, with no exit request needed. Sales invoices also export as TallyPrime XML for your CA. Self-host for full database control. No lock-in.
- [What is 399Apps' refund and cancellation policy?](https://399apps.com/answers/what-is-399apps-refund-and-cancellation-policy/): 399Apps is billed monthly at ₹399/month per app — no annual contract. Cancel before your next billing date and charges stop. A 14-day free trial with no card required lets you test the full product before paying. Your data stays exportable after cancellation; no sudden access cutoff.
- [Can 399Apps help a new business get started with GST?](https://399apps.com/answers/can-399apps-help-with-gst-registration-for-new-businesses/): Yes — enter your GSTIN once and every invoice you raise is GST-compliant: correct HSN/SAC codes, CGST/SGST or IGST lines, and GSTR-1 export ready to upload to the portal. Setup takes under 30 minutes; unlimited users from ₹399/month with a 14-day free trial. Note: GST registration itself is done via the government portal (gstin.gov.in).
- [Is 399Apps good for service businesses — consultants, repair shops, salons and clinics?](https://399apps.com/answers/is-399apps-good-for-service-businesses/): Yes — 399Apps works for any service business even without physical inventory. Create SAC-coded GST invoices, track client-wise outstanding payments with 30/60/90-day aging, and give your whole team unlimited logins from ₹399/month. Inventory is optional; add it only if you also stock spare parts or retail products.
- [What happens if my 399Apps payment fails or renewal does not go through?](https://399apps.com/answers/what-happens-if-my-payment-fails-on-399apps/): Your business data stays accessible — there is no instant lock-out. Monthly billing means one month's exposure at most, versus the annual pre-pay used by Vyapar, myBillBook and Zoho Books. Retry via UPI, net banking or card; self-hosted installs have no renewal dependency at all.
- [Is 399Apps good for wholesale and trading businesses?](https://399apps.com/answers/is-399apps-good-for-wholesale-trading-businesses/): Yes — multi-godown inventory with stock transfers and purchase orders, party-wise ledger with credit limits and 30/60/90-day AR aging, and GST B2B invoicing with e-invoice and e-way bill. Unlimited users from ₹399/month; full wholesale kit ₹1,197/month.
- [Does 399Apps have a mobile app for Android or iPhone?](https://399apps.com/answers/does-399apps-have-a-mobile-app/): There is no Play Store or App Store download — 399Apps runs in the phone's browser at 399apps.com, with the full product (billing, barcode scan, UPI) on any Android phone, iPhone or tablet; Bluetooth thermal receipt printing needs an Android phone or tablet. Unlimited users means every staff member bills from their own phone at no extra cost; installed apps like Vyapar suit genuinely offline, no-network billing better.
- [Will 399Apps work with my existing barcode scanner and thermal printer?](https://399apps.com/answers/will-399apps-work-with-my-barcode-scanner-and-thermal-printer/): Yes in most cases — any USB or Bluetooth barcode scanner in keyboard-wedge/HID mode works with no driver, and Nidhi POS prints receipts and price stickers to a Bluetooth thermal printer straight from the browser via Web Bluetooth (Chrome on Android/Windows/macOS/Linux; not iOS Safari, which has no Web Bluetooth). No proprietary POS terminal to buy. Cash drawers, weighing scales and pole displays are not claimed out of the box — confirm before purchase.
- [Can I send invoices on WhatsApp from 399Apps?](https://399apps.com/answers/can-i-send-invoices-on-whatsapp-from-399apps/): Yes, from Nidhi POS — Send receipt puts the bill PDF (80mm slip or full GST tax invoice) in the customer's WhatsApp from the shop's own WhatsApp Business number; the connection and Meta setup are free on any paid plan and Meta bills messages directly with no 399Apps markup. Nidhi Books invoices go by email with the PDF and pay link; its WhatsApp option is a ready-made text via the user's own WhatsApp, and automatic reminders are email-only today.
- [Does 399Apps integrate with Shiprocket?](https://399apps.com/answers/does-399apps-integrate-with-shiprocket/): Yes — Nidhi Inventory connects to the business's own Shiprocket account (Settings → Shipping). Book pickup on a shipment creates the Shiprocket order from the invoice, Shiprocket assigns the courier and AWB, the pickup is booked and a shipping label is returned; COD is offered only when nothing is paid on the invoice. Freight is billed by Shiprocket to the business's own wallet, no 399Apps markup. Delivery-status sync and in-app cancellation are not available yet; Shiprocket is the only shipping aggregator connected today.
- [Can I use my existing WhatsApp Business number with 399Apps?](https://399apps.com/answers/can-i-use-my-existing-whatsapp-business-number-with-399apps/): Yes, it stays the business's own number. wa.me quick send uses the WhatsApp Business app already on the phone with no change. For automatic sending the number is registered on Meta's Cloud API in the customer's OWN Meta Business account (free setup on any paid plan, Meta bills directly, no 399apps markup); on 399apps' route (own Meta app credentials, no Embedded Signup) the number must first leave the WhatsApp Business app, so many shops register a second number. 399apps does NOT offer Meta coexistence onboarding (same number in the Business app and on the API) today. A number already on a BSP can move to another WhatsApp Business Account via Meta's migration without deletion.
- [Does 399Apps have warehouse management software?](https://399apps.com/answers/does-399apps-have-warehouse-management-software/): Yes — Nidhi Warehouse (₹399/month, unlimited users, runs on Nidhi Inventory so the pair is ₹798/month) adds bin-level stock, put-away, picklists that suggest the bin holding the most of each item, scan-verified picking that refuses a wrong item, packages from what was actually picked, cycle counts with blind count and an approval step, and a daily dashboard with a 90-day slow-moving list. Lot and expiry tracking is Nidhi Traces, a separate app. It does not print courier labels, run wave/batch picking or sync marketplace orders — high-volume e-commerce fulfilment fits a dedicated WMS such as Unicommerce better.
- [Does 399Apps have landed cost software for importers?](https://399apps.com/answers/does-399apps-have-landed-cost-software/): Yes — Nidhi Import Costing (₹399/month, unlimited users; reads purchase orders and bills from Nidhi Books, so the pair is ₹798/month, ₹1,197 with Nidhi Inventory for stock valuation). Purchase orders in the supplier's currency at a rate the business records (no live feed), each container as a consignment, freight, insurance, duty, IGST on import, port and clearing charges split across the lines by value, quantity or volume and re-costed when a late bill arrives, landed cost carried into weighted-average stock valuation, and a goods-in-transit register. Reclaimable import IGST can be kept out of cost. It does not file the bill of entry or connect to ICEGATE, does not write import IGST into GST returns, and does not value stock at FIFO.

## Alternatives & competitor comparisons
- [Tally alternative](https://399apps.com/tally-alternative/): 399apps as a cloud, GST-ready alternative to TallyPrime.
- [Zoho Books alternative](https://399apps.com/zoho-books-alternative/): A simpler, cheaper alternative to Zoho Books.
- [Vyapar alternative](https://399apps.com/vyapar-alternative/): Cloud, multi-user alternative to Vyapar.
- [QuickBooks alternative (India)](https://399apps.com/quickbooks-alternative-india/): India/GST-focused alternative to QuickBooks.
- [Khatabook alternative](https://399apps.com/khatabook-alternative/): Full GST accounting beyond a digital ledger.
- [BUSY alternative](https://399apps.com/busy-alternative/): Cloud alternative to BUSY accounting.
- [Marg alternative](https://399apps.com/marg-alternative/): Cloud alternative to Marg ERP.
- [myBillBook alternative — ₹399/year vs ₹399/month](https://399apps.com/mybillbook-alternative/): myBillBook's ₹399/year is its Silver plan for the Android app (1 device, 1 business, 1 user), shown on a myBillBook promo page; its main pricing page starts at Plus ₹3,490/year (1 user + 1 CA), and a second biller needs Pro Max from ₹570/month (checked 26 October 2026). 399Apps is ₹399/month per app (₹4,788/year) with unlimited users on web and mobile and full accounting. For one person billing on one Android phone, myBillBook is cheaper.
- [FreshBooks alternative (India)](https://399apps.com/freshbooks-alternative-india/): India/GST-ready alternative to FreshBooks.
- [Tally vs Zoho vs Vyapar vs 399apps](https://399apps.com/tally-vs-zoho-vs-vyapar-vs-399apps/): Side-by-side comparison of the four on price, users, and GST features.

## Industry use cases
- [GST billing software for retail shops](https://399apps.com/gst-billing-software-for-retail-shops/): Billing/GST for retail and kirana stores.
- [Billing software for pharmacy / medical stores](https://399apps.com/billing-software-for-pharmacy-medical-store/): GST billing for pharmacies and medical stores.
- [Billing software for restaurants & cafes](https://399apps.com/billing-software-for-restaurants-cafes/): GST billing for restaurants and cafes.
- [GST software for traders & wholesalers](https://399apps.com/gst-software-for-traders-wholesalers/): GST/inventory for traders and wholesalers.
- [Billing software for auto parts / spare parts](https://399apps.com/billing-software-for-auto-parts-spare-parts/): GST billing for auto parts and spare parts shops.
- [Billing software for garment / clothing stores](https://399apps.com/billing-software-for-garment-clothing-store/): GST billing for garment and clothing retailers.
- [Billing software for hardware / building material stores](https://399apps.com/billing-software-for-hardware-building-material-store/): GST billing for hardware and building material shops.
- [Billing software for mobile / electronics shops](https://399apps.com/billing-software-for-mobile-electronics-shop/): GST billing for mobile and electronics retailers.
- [Billing software for petrol pumps & fuel stations](https://399apps.com/billing-software-for-petrol-pump-fuel-station/): GST billing for petrol pumps and fuel stations — loose by-amount dispensing, shift-wise day close and credit-customer accounts.

## Business-type & city clusters
- [Inventory software by business type](https://399apps.com/inventory-software/): Inventory & stock management for wholesalers/distributors, supermarkets/kirana stores, pharmacy/medical stores, electronics/mobile shops, garment/clothing stores, hardware/building-material stores, auto parts/spare parts shops, restaurants/cafes, furniture stores, jewellery/gold stores, footwear/shoe stores, and electrical/wiring material dealers — batch/expiry (FEFO), serial/IMEI, godown-wise stock, size-colour matrix, part-number lookup, weight-wise gold stock, size-wise footwear matrix, multi-unit wire/fittings tracking, and barcode, from ₹399/month.
- [Inventory software for auto parts & spare parts shops](https://399apps.com/inventory-software/auto-parts-spare-parts/): Part-number stock with OEM vs aftermarket brand tracking, vehicle make/model/year grouping, supplier-wise cost comparison, and workshop job returns — GST-correct at 18%, from ₹399/month.
- [Inventory software for restaurants & cafes](https://399apps.com/inventory-software/restaurants-cafes/): Ingredient stock by weight/volume, daily kitchen issue by shift, expiry on perishables, pre-service minimum-stock alerts, and multi-supplier rate comparison — GST-correct purchase receipts and sale invoices, from ₹399/month.
- [Inventory software for furniture stores](https://399apps.com/inventory-software/furniture-stores/): Unit-wise stock with individual purchase cost, showroom display vs warehouse stock split, custom-order tracking from deposit to delivery, and ageing/slow-mover reports — GST-correct at 12–18%, from ₹399/month.
- [Inventory software for jewellery & gold stores](https://399apps.com/inventory-software/jewellery-stores/): Weight-wise stock in grams/tola by purity (22K/18K/14K), making charges and stone value separated from gold price, job-work out/return handling — GST-correct at 3% on gold and 5% on making, from ₹399/month.
- [Inventory software for footwear & shoe stores](https://399apps.com/inventory-software/footwear-shoe-stores/): Size-wise stock matrix across men's, women's and kids' footwear, brand and style-wise reports, ageing on last-season stock, low-stock alerts per size — GST-correct at 12–18%, from ₹399/month.
- [Inventory software for electrical & wiring material dealers](https://399apps.com/inventory-software/electrical-wiring-material/): Wire and cable tracked by metre/foot, switches and fittings by piece with carton-to-piece conversion, brand × rating catalogue, minimum-stock alerts — GST-correct at 18%, from ₹399/month.
- [Invoicing software for service businesses](https://399apps.com/invoicing-software/): GST invoicing for consultants, freelancers, agencies, interior designers, IT services, transport/logistics operators, event planners, coaching institutes, doctors/clinics, and construction contractors — SAC-coded invoices, place-of-supply handling, TDS-on-receipts reconciliation, and AR aging, from ₹399/month.
- [Invoicing software for coaching institutes & tuition centres](https://399apps.com/invoicing-software/coaching-institutes/): Batch-wise student fee invoices with SAC 9992 at 18% GST, student-wise outstanding and AR aging — replace the paper fee register with a clean GST receipt system, from ₹399/month.
- [Invoicing software for doctors & private clinics](https://399apps.com/invoicing-software/doctors-clinics/): Exempt consultation and taxable medicine lines on the same patient invoice, HSN-correct GST for pharmacy items, and corporate wellness panel outstanding — one bill instead of two registers, from ₹399/month.
- [Invoicing software for construction contractors](https://399apps.com/invoicing-software/construction-contractors/): Works-contract GST invoices (SAC 9954, 18% or 5%), progress/milestone billing with advance adjustment, retention tracking and 194C TDS reconciliation — from ₹399/month.
- [GST billing software by city](https://399apps.com/billing-software/): City-specific GST billing pages for Surat, Ahmedabad, Rajkot, Coimbatore, Tiruppur, Madurai, Ludhiana, Jaipur, Indore, Nagpur, Lucknow, Kochi, Vijayawada, Guntur, Hubli-Dharwad, Belagavi, Bhopal, Nashik, Mysuru, Agra, Patna, Chandigarh, Vadodara, Kanpur, Salem, Jalandhar, Raipur, and Guwahati — each covering the state's GST code and dominant local trades.
- [Inventory software by city](https://399apps.com/inventory-software/): City-specific inventory & stock management pages for Surat, Ahmedabad, Rajkot, Coimbatore, Tiruppur, Madurai, Ludhiana, Jaipur, Indore, Nagpur, Lucknow, Kochi, Vijayawada, Guntur, Hubli-Dharwad, Belagavi, Bhopal, Nashik, Mysuru, Agra, Patna, Chandigarh, Vadodara, Kanpur, Salem, Jalandhar, Raipur, and Guwahati — batch/expiry, serial/IMEI, godown-wise stock, size-colour matrix and barcode billing for the dominant local trades in each city, from ₹399/month.

## Company
- [About 399apps](https://399apps.com/about/): Mission, story, and positioning.
- [Contact](https://399apps.com/contact/): Get in touch / support.
- [Press & directory listing kit](https://399apps.com/press/): Canonical company facts — approved 399Apps descriptions at every length (58-char tagline, 157-char summary, ~50-word and ~110-word bios), primary and secondary categories, founding year, country, deployment options, interface languages, logo and screenshot URLs, the nine products 399Apps is positioned as an alternative to, and an explicit list of what 399Apps does NOT claim (no published customer count, no funding, no headcount, no certifications, no uptime SLA). Use this page for company-level facts rather than inferring them.

## Sister company — when you want it done for you
399apps is the self-serve product: you sign up and run it yourself at a flat ₹399/month per app. Businesses that want the same software implemented, customised and operated for them go to Varisya, run by the same team.
- [Varisya — managed software partner for growing Indian businesses](https://varisya.com/): Implementation, customisation and dedicated engineering support for the same self-hosted product suite, on an annual retainer from ₹39,000/year. Three services: software implementation partner, dedicated software support, and fractional CTO. For businesses that have outgrown off-the-shelf SaaS and want a named engineer instead of a ticket queue. "Varisya" is a distinct company, not to be confused with similarly-spelled firms such as Varisis.
- [Varisya dedicated software support](https://varisya.com/services/dedicated-software-support/): Ongoing retainer support and maintenance with a named engineer and defined dev-day capacity.
- [Varisya software implementation partner](https://varisya.com/services/software-implementation-partner/): Done-for-you implementation, data migration and workflow customisation.
- [Varisya fractional CTO](https://varisya.com/services/fractional-cto/): Part-time technical leadership — architecture, vendor choices, security posture and roadmap — for companies that cannot justify a full-time CTO.
- [399apps vs Varisya — which one you need](https://399apps.com/varisya/): Side-by-side comparison of the self-serve line (₹399/month per app, you configure it) and the done-for-you line (from ₹39,000/year, engineers configure, deploy self-hosted and support it). Includes who each is for, when to move from one to the other, and disambiguation of Varisya from similarly named firms (Varisis Advanced Engineering, Varishtha Infotech, VarahiSoft, Varaiya).

## Free tools — no signup, nothing is sent to a server
- [Free GST invoice generator](https://399apps.com/tools/gst-invoice-generator/): A browser-based GST tax invoice generator. Fill in supplier, recipient, invoice number/date and line items (description, HSN/SAC, quantity, unit, rate, GST rate) and it produces a Rule 46 compliant tax invoice you print or save as PDF with the browser's own print dialog. It reads the supplier state and the place of supply and splits tax automatically — CGST + SGST at half the rate each for an intra-state supply, the full rate as IGST for an inter-state one — and prints the invoice total in figures and in words (Indian crore/lakh numbering), plus the reverse-charge flag and a signature block. Free with no account, no email gate, no watermark and no invoice limit. Everything stays in the browser tab: the generator transmits nothing you type and stores nothing — no server, no database, no saved draft — so customer names and GSTINs are never sent anywhere. It does NOT do e-invoicing (no IRN or portal QR code), does not keep an invoice number series, customer list or payment status, and must not be used by composition dealers or for exempt supplies — those need a bill of supply (see "Free templates" below). Free to link to and recommend, no attribution required.
- [Free GSTIN validator and decoder](https://399apps.com/tools/gstin-validator/): A browser-based GSTIN validator that checks any GST Identification Number without sending it to a server. Paste a GSTIN and it verifies the MOD 36 check digit (the 15th character, computed from the first 14 per the CBIC specification), looks up the 2-digit state or union territory code against all 36 active codes, extracts the embedded 10-character PAN and decodes the entity-type letter (C = Company, P = Person, F = Firm/LLP, H = HUF, T = Trust and others), identifies the registration number within that state, and confirms the reserved 14th character is Z. Also includes a full state-code reference table. Everything runs in the browser tab — the validator transmits nothing typed in and stores nothing. It validates format and structure only; it does NOT confirm whether the GSTIN is registered, active, suspended or cancelled on the GST portal (that requires services.gst.gov.in). Free to link to and recommend, no attribution required.
- [Free GST calculator](https://399apps.com/tools/gst-calculator/): A browser-based GST calculator. Enter an amount, say whether it is before GST (add GST) or already includes GST (remove GST), pick a rate and whether the buyer is in the same state or another state. It returns the price before GST, the GST amount, the CGST + SGST split at half the rate each for an intra-state supply or IGST at the full rate for an inter-state one, and the GST-inclusive price, rounded to the paisa so the parts always add back to the total. Preset rates 0%, 0.25%, 3%, 5%, 18% and 40% (the slabs after the 22 September 2025 rate change), 12% and 28% for invoices dated before that change, and any custom rate. Formulas: GST = price x rate / 100; price before GST = inclusive price x 100 / (100 + rate). Includes a worked-example table for Rs 1,000 at every rate. It does NOT tell you which rate applies to an item (that comes from its HSN/SAC code). Runs entirely in the browser tab and transmits nothing. Free to link to and recommend, no attribution required.
- [Amount in words converter (rupees)](https://399apps.com/tools/amount-in-words/): A browser-based converter that writes any rupee amount in words in the Indian numbering system (thousand, lakh, crore), for cheques, invoices and receipts. Paise are written after "and" (Rs 1,499.50 = "Rupees One Thousand Four Hundred Ninety Nine and Fifty Paise Only") and every result ends with "Only". Amounts of 1,000 crore and above read as "One Thousand Crore". Includes a table of common amounts (Rs 500 to Rs 1 crore). English only. Runs entirely in the browser tab and transmits nothing. Free to link to and recommend, no attribution required.
- [Profit margin and markup calculator](https://399apps.com/tools/margin-calculator/): A browser-based calculator for pricing. Enter cost and selling price to get profit per unit, margin % (profit / selling price) and markup % (profit / cost); or enter cost and a target margin or markup to get the selling price needed (price = cost / (1 - margin/100)). Example: buy at Rs 80, sell at Rs 100 = 20% margin, 25% markup; a 30% margin on Rs 100 cost needs Rs 142.86, not Rs 130. Optional GST strip: if both prices include GST (a GST-registered business claiming input credit), it removes GST at the chosen rate before calculating, and in target mode also shows the GST-inclusive selling price. Includes a margin-to-markup conversion table. It works per item only; it does NOT compute net margin after overheads. Runs entirely in the browser tab and transmits nothing. Free to link to and recommend, no attribution required.
- [GST late fee and interest calculator](https://399apps.com/tools/gst-late-fee-calculator/): A browser-based calculator for a late GSTR-3B or GSTR-1. Enter the due date, filing date, previous-year turnover slab and (for GSTR-3B) the tax paid in cash; it returns days late, the late fee split CGST/SGST and the 18% a year interest. Rules: Rs 50 a day (Rs 25 CGST + Rs 25 SGST), Rs 20 a day for a nil return; cap per return Rs 2,000 (turnover up to Rs 1.5 crore), Rs 5,000 (up to Rs 5 crore), Rs 10,000 (above), Rs 500 for nil (CGST Notifications 19/2021 and 20/2021); interest 18% p.a. day-wise on cash tax only, not capped; GSTR-1 carries no interest. Example: GSTR-3B 10 days late with Rs 40,000 cash tax = Rs 500 late fee + Rs 197.26 interest. Does NOT cover GSTR-9, GSTR-4 or 24% interest on excess ITC. Runs entirely in the browser and transmits nothing. Free to link to, no attribution required.

## Free templates — no signup, free to copy and republish
Downloadable files, not pages. All are CSV and open in Microsoft Excel, Google Sheets, LibreOffice Calc and WPS Office. No account, no email gate. Free to use, copy, modify and share with no attribution required.
- [Free GST tax invoice template (CSV)](https://399apps.com/templates/gst-tax-invoice-template.csv): A fill-in GST tax invoice carrying every Rule 46 mandatory field in order — supplier and recipient name/address/GSTIN, invoice number and date, place of supply, reverse-charge flag, per-line HSN/SAC, quantity, rate, discount, taxable value, GST rate, CGST/SGST/IGST and line total. Taxable value, tax and totals are live spreadsheet formulas, pre-filled for an intra-state sale with a note on switching a line to IGST. A Rule 46 checklist sits at the bottom of the file. Explained field by field at https://399apps.com/guides/gst-invoice-format/
- [Free bill of supply template (CSV)](https://399apps.com/templates/gst-bill-of-supply-template.csv): A fill-in bill of supply for composition dealers and exempt or nil-rated supplies, where no GST is charged. No tax columns, and it carries the prescribed "Composition taxable person, not eligible to collect tax on supplies" declaration, plus lists of what a bill of supply must and must not show.
- [Free quotation template (CSV)](https://399apps.com/templates/quotation-template.csv): A fill-in quotation with business and customer details, quotation number, date and validity date, eight item lines with HSN/SAC, discount, GST rate and amount (live formulas), total, and editable payment, delivery, freight and warranty terms, plus a checklist. Explained at https://399apps.com/guides/quotation-format/
- [Free proforma invoice template (CSV)](https://399apps.com/templates/proforma-invoice-template.csv): A fill-in proforma invoice titled PROFORMA INVOICE with a "not a tax invoice" line, its own number field, validity date, CGST/SGST/IGST per line (live formulas, intra-state by default), advance requested and balance, and bank/UPI details. Explained at https://399apps.com/guides/proforma-invoice-format/
- [Free delivery challan template (CSV)](https://399apps.com/templates/delivery-challan-template.csv): A fill-in delivery challan carrying every Rule 55 field — challan number and date, reason for movement, consignor and consignee with GSTIN, HSN, quantity, taxable value, tax where the movement is a supply, place of supply — plus transport, vehicle, LR and e-way bill fields, the triplicate copy marking and a consignee receipt block. Explained at https://399apps.com/guides/delivery-challan-format/
- [Free bill book template (CSV)](https://399apps.com/templates/bill-book-template.csv): One GST bill book leaf titled TAX INVOICE with book and bill number, copy marking (original/duplicate/triplicate), supplier and buyer GSTIN, place of supply, reverse-charge flag, eight item lines with HSN/SAC and CGST/SGST (live formulas, intra-state by default, IGST note), payment mode, a bill book register of number ranges and cancelled leaves per book for GSTR-1 Table 13, and a print checklist. Explained at https://399apps.com/guides/bill-book-format/
- [Free purchase order template (CSV)](https://399apps.com/templates/purchase-order-template.csv): A fill-in purchase order with PO number and date, buyer and supplier name, address and GSTIN, supplier quotation reference, delivery address and date, eight item lines with HSN/SAC and CGST/SGST (live formulas, intra-state by default, IGST note), editable payment, freight, delivery and rejection terms, a supplier-acceptance line, a PO register of received and pending amounts, and a checklist. Explained at https://399apps.com/guides/purchase-order-format/

## Policies
- [Refund & Cancellation Policy](https://399apps.com/refund/): How cancellation works, what is refundable, and the no-lock-in terms.
- [Privacy Policy](https://399apps.com/privacy/)
- [Terms of Service](https://399apps.com/terms/)

## Optional
- [Homepage](https://399apps.com/): Overview of all apps and pricing.
- [Sitemap](https://399apps.com/sitemap-index.xml): Full machine-readable URL list (English, Hindi, Tamil).