What is GST billing software?
GST billing software makes a bill that follows India's GST rules: the correct HSN/SAC code on each item, the right CGST/SGST/IGST split depending on where you are selling to, and — for businesses above the ₹5 crore turnover limit — registering the invoice with the government, which sends back an IRN number and a signed QR code to print on it. Good GST billing software also makes the e-way bill from the same invoice when the goods move, and keeps your GSTR-1 figures agreeing with your books, so filing is a summary of what you already did rather than a month of corrections.
Mandatory fields on a GST invoice
A valid GST tax invoice must carry these details — billing software should enforce them so no document goes out incomplete:
GST invoice mandatory fields checklist
| Field | Why it matters |
|---|
| Supplier name, address & GSTIN | Identifies the taxpayer issuing the document |
| Consecutive invoice number & date | Sequence integrity for returns and audit |
| Buyer name, address & GSTIN (B2B) | Enables the buyer's input tax credit |
| HSN/SAC code per item | Classifies goods/services; 4 or 6 digits by turnover |
| Quantity, rate, taxable value & discounts | The basis on which tax is computed |
| CGST/SGST/IGST rate and amount | Correct split depends on place of supply |
| Place of supply & reverse charge note | Determines which state receives the tax |
| Signature or digital signature | Authenticates the document |
For e-invoicing taxpayers, the IRN and signed QR code from the IRP are also required on B2B documents.
Free vs paid GST billing software
A free billing app makes a PDF. The cost turns up later — at filing time, when the bills and the books do not agree and someone has to fix them one by one. PeppyBooks puts every invoice straight into your accounts, takes the stock down, and keeps your GSTR-1 data correct as you go. That is what actually saves your accountant's hours, and yours. Plans start at $17 per user per month with a free 14-day trial, so the test is easy: bill for a week and see whether filing gets easier.
