GST Billing Software for Retail Shops: Custom vs Ready-Made

Description

Solution Billing and POS software for retail shops

Most single shops should buy a ready-made GST billing app. Custom billing software is worth building when your pricing, units or stock rules do not fit one: weight plus making charge, rates by customer, cloth sold by the metre, several stores on one stock. WavX builds that kind of billing system. The WavX cost model puts it at roughly ₹2.6 lakh to ₹10 lakh.

Tell us what you need built Last updated 2 October 2026

Start with a ready-made app, unless one of these is true

A ready-made GST billing app is the right answer for most single shops. It prints a valid invoice, keeps a simple stock count, takes cash and UPI, and costs little each month. Custom billing software earns its price only when the shop has a rule the app cannot express. These are the rules that usually push a shop to custom:

What the shop needs

Why ready-made apps struggle

What custom software does instead

Price built from parts: weight × day's rate + making charge + stone value

Apps price an item, not a formula

Calculates the bill from the rate entered that morning

One item sold in several units: piece, box, kg, metre, feet

Unit conversion is often fixed or missing

Stores conversion per item; stock stays in one base unit

Different rates for walk-in, contractor and wholesale buyers

One price list, or a flat discount

Rate list per customer group, with who may override it

Credit customers who pay monthly

Basic ledgers without reminders or limits

Credit limit per customer, statements, WhatsApp reminders

Several stores or a godown sharing stock

Each store as a separate account

One stock figure with transfers between locations

Billing must update an online store or ERP

Exports that someone re-enters by hand

Pushes each sale to the other system

If none of these applies, buy the app. If one does, the comparison in POS software for retail: custom vs ready-made walks through the trade-off in more depth.

What each type of shop needs from its billing

The same word, billing, means different software in different shops. WavX has published a cost guide for each of the five below; the table shows what is particular to each.

Shop

The hard part of billing

Features that matter

Cost guide

Hardware and sanitaryware

Thousands of items with sizes and grades; the same pipe sold per piece and per length; contractor accounts

Unit conversion, size and grade variants, customer-wise rates, quotation to bill, credit ledger

Hardware shop billing

Kirana and general store

Many small bills fast; loose items by weight; regular customers on credit

Fast keyboard or scanner billing, weighing-scale items, udhaar ledger, supplier purchase entry

Kirana store billing

Textile and garments

Fabric by the metre, ready-made garments by size and colour; tags printed in the shop

Size-colour matrix, barcode label printing, cut-piece and remnant stock, salesperson-wise sales

Textile shop billing

Jewellery

Price changes with the gold or silver rate; net and gross weight; making and stone charges; old gold taken in exchange

Daily rate entry, weight-based pricing formula, HUID per item, old-gold purchase against a sale, scheme and advance booking

Jewellery billing

Sweet shop

Sold by weight and by box; short shelf life; festival rush and advance orders

Weight billing, box combinations, batch date and wastage, bulk and party orders with advance payment

Sweet shop billing

Jewellery: the hallmark number belongs on the item record

The Bureau of Indian Standards describes the Hallmark Unique Identification (HUID) as a six-digit alphanumeric number, unique to each hallmarked item and traceable, and part of the hallmark since 1 July 2021 alongside the BIS logo and the purity mark. BIS lists exemptions to mandatory hallmarking, among them articles under 2 grams and jewellers with annual turnover below ₹40 lakh. For billing software this means:

Each tagged piece is stored with its HUID, purity, gross weight and net weight.

The invoice can print the HUID of every piece sold.

Exempt pieces are marked as such rather than left blank.

How the rules apply to your shop is for your accountant and BIS guidance to decide. The software's job is to hold the data and print it.

GST on the bill

Every shop type shares the same tax core. Rule 46 of the CGST Rules sets what a tax invoice must carry, including a consecutive serial number of at most sixteen characters that is unique for the financial year. Billing software therefore stores the full HSN code and tax rate for each item, numbers each counter from its own series, and keeps rates as dated settings rather than code, so a rate change does not rewrite old bills.

The full list of invoice fields, the small-bill relaxation, HSN digit rules and the 2025 rate changes are set out on the custom POS software page, with sources. Most retail shops selling to consumers do not need e-invoicing. A shop above the notified turnover that also bills registered businesses may; the GST e-invoicing integration page explains when and how.

Hardware on the counter

No hardware brand is assumed. The exact models on your counter are tested before a quote is fixed.

Device

Used by

What to check

Thermal receipt printer

Every shop

Paper width (2-inch or 3-inch), connection, and whether it prints your bill language

Barcode scanner

Kirana, textile, hardware

That the billing screen keeps focus on the scan field

Label printer

Textile, jewellery, hardware

Label size, and whether the barcode encodes price or weight

Weighing scale

Kirana, sweet shop, jewellery

Whether the scale has a documented data output; if not, weight is typed in

Cash drawer

Most shops

Whether it opens from the receipt printer

A4 printer

Hardware, jewellery, wholesale

For full GST invoices and quotations to business buyers

A billing system that runs in a web browser cannot always reach a USB printer directly. The POS page explains the three ways round it.

What WavX builds

WavX builds retail billing as a web application with a fast counter screen, in React and Node.js with PostgreSQL. Typical modules:

Module

What it covers

Counter billing

Scan or search, quantity in any unit, discount rules, hold and recall, print or WhatsApp the bill

Item master

HSN, tax rate, units and conversions, variants, barcodes, price lists

Stock

Sale, purchase, transfer, stock count, batch or HUID where needed

Customers and credit

Lookup by phone, credit limit, ledger, statements and reminders

Purchases and suppliers

Supplier bills, returns, payments due

Day end

Cash count, UPI and card totals, the day's sales and tax summary

Reports

Sales by item, category, salesperson and store; margin; slow-moving stock

Accounting link

Sales and tax data to Tally or to your accountant

If stock is the bigger problem than billing, start with inventory management software . For a Hinglish walkthrough of the same decision, see billing software banwane ka kharcha .

Planning range

These figures come from the WavX cost model behind the software cost estimator . The range is the subtotal less 15% to the subtotal plus 25%. It is a planning range, not a quote.

Scenario

Cost model inputs

Subtotal

Timeline band

Single-shop billing

Internal tool base ₹2,00,000; roles ₹60,000; exports and reporting ₹50,000

₹3,10,000

₹2,63,500 to ₹3,87,500

4–8 weeks

Shop-specific pricing, stock and credit

Custom web application base ₹4,50,000; roles ₹60,000; admin panel ₹90,000; exports and reporting ₹50,000

₹6,50,000

₹5,52,500 to ₹8,12,500

8–14 weeks

Several stores with payments and an accounting link

Custom web application base ₹4,50,000; roles ₹60,000; payments and billing ₹90,000; admin panel ₹90,000; exports and reporting ₹50,000; third-party integrations ₹60,000

₹8,00,000

₹6,80,000 to ₹10,00,000

Assumptions: small scale (multiplier 1.0), standard interface design, hardware bought separately, offline-first billing not included. Yearly maintenance is 15–25% of the build cost, as set out in the maintenance cost guide . The shop-specific cost guides linked above also compare ready-made subscription prices.

How the build runs

Counter visit. Watch how bills are made today, list every price and discount rule, collect sample bills and the hardware model numbers.

Item list and tax setup. Import items with HSN codes, rates and units, agreed with your accountant.

Billing screen first. Built and shown to the cashier before anything else, because counter speed decides whether staff accept the system.

Stock, credit and purchases. Added once billing is right.

Hardware test. On your printers, scanners and scales, with your paper and labels.

Parallel run. A few days beside the old method, comparing the day-end totals.

Go live and train. Counter by counter, store by store.

The source code and the data belong to you at the end.

When you should not build

You run one shop and your pricing is ordinary. Buy a ready-made app.

The real problem is accounts, not the counter. A ready-made accounting package with billing may cover it.

You are not sure what you need yet. Use a ready-made app for a season and note every place it falls short. That list becomes the specification, and it is often shorter than expected.

Retail billing is one of the systems WavX builds for retail businesses , under custom software and business systems .

Frequently asked questions

Do I need custom billing software for one shop?

Usually not. A ready-made GST billing app handles barcode items, GST invoices, a few payment modes and basic stock for a small monthly fee or less. Custom software is worth it when the app cannot follow a pricing or stock rule your shop depends on, or when you run several stores and want one system you own.

How much does custom retail billing software cost?

The WavX cost model gives planning ranges of about ₹2.6 lakh to ₹3.9 lakh for single-shop billing, ₹5.5 lakh to ₹8.1 lakh for billing with shop-specific pricing and stock, and ₹6.8 lakh to ₹10 lakh for several stores with payments and an accounting link. These are planning ranges, not quotes. Hardware is bought separately.

Which printers, scanners and weighing scales will it work with?

We ask for the exact model numbers on your counter and test them before fixing the quote. Most USB barcode scanners work with no integration. Receipt printers, label printers and weighing scales vary by maker, and a scale is only connectable if it has a documented data output.

Can it keep billing when the internet is down?

Yes, if offline billing is designed in from the start. Each counter keeps the item list locally, numbers bills from its own series and syncs later. It costs more to build and test, so it is worth it only if outages actually stop your counter today.

Will it send my sales to Tally?

It can. Sales, returns and tax totals can be pushed to Tally bill by bill or as a daily summary. Which one suits you depends on how your accountant works, so we agree it with them before building.

Sources

CBIC: Rule 46 of the CGST Rules, 2017 (tax invoice) · read 2 October 2026

BIS: Hallmarking FAQ (HUID) · read 2 October 2026

BIS: Hallmarking FAQ, mandatory system (exemptions) · read 2 October 2026

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