GSTR-1 vs GSTR-3B: What Each GST Return Actually Requires
GSTR-1 lists every outward sale invoice by invoice and feeds your buyers' input tax credit. GSTR-3B is the summary return that declares tax liability and ITC, and it is where payment happens. GSTR-1 is generally due on the 11th and GSTR-3B on the 20th of the next month, and mismatches between them trigger notices.
GSTR-1 and GSTR-3B are the two returns most regular GST taxpayers file every month, or every quarter under the QRMP scheme. They report different things, and confusing them is a common reason businesses end up answering notices months later.
What each one covers
| GSTR-1 | GSTR-3B | |
|---|---|---|
| What it reports | Every outward sale, invoice by invoice | A summary of tax liability and input tax credit |
| Detail level | Detailed | Summary |
| Why it matters | Feeds your buyers' input tax credit | Is where tax is actually paid |
| Typical due date | 11th of the next month | 20th of the next month |
Due dates shift slightly for quarterly filers and may be extended by notification, so check the current dates on the GST portal.
Why the two must agree
The sales you report in GSTR-1 appear in your buyers' auto-drafted statements, and they claim credit on that basis. The totals in GSTR-3B must be consistent with what you reported in GSTR-1. If they are not, the system flags the difference and you may receive a notice, and your buyers may lose credit.
Common causes of mismatch
- ✓Invoices added to the books after GSTR-1 was filed
- ✓Credit notes or debit notes included in one return and left out of the other
- ✓Amendments filed in a later month and not carried across
- ✓Different people preparing each return from separate spreadsheets
- ✓Wrong place of supply, which changes the split between IGST and CGST or SGST
How to keep them in line
- Close the month's sales in your books before you prepare either return.
- Generate GSTR-1 from the invoice data and reconcile its totals to the sales ledger.
- Prepare GSTR-3B from the same ledger, and compare the outward supply totals with GSTR-1.
- Match your purchase credit against the auto-drafted statement before you claim it.
- Record every adjustment, with the reason.
Check before you file
| Check | Why |
|---|---|
| Sales per books equal sales per GSTR-1 | Catches missing invoices |
| Outward supply per GSTR-3B equals GSTR-1 | Avoids system flags |
| Credit and debit notes are in both | Keeps tax liability right |
| ITC claimed is supported by the supplier's statement | Avoids reversal later |
Where software helps
If both returns come from the same invoice data, the totals match by construction. That removes the separate reconciliation step that a spreadsheet process needs every month.
Written by
Founder, Airwix Technologies (Sleet)
Vatsal Sutariya is the founder of Airwix Technologies in Ahmedabad, the company that builds Sleet: SleetHR for HR and payroll, and Sleet Accounting for GST billing and books. He writes about GST, invoicing, business tax and choosing software for Indian businesses, and checks each rule against the official notification before it is published.
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