How to file GSTR-1 without mismatches
GSTR-1 is a statement of what you sold, and almost every problem with it starts on the invoice rather than in the return. A missing customer GSTIN or a wrong place of supply cannot be fixed at filing time without amending the document it came from.
| Table | Contains |
|---|---|
| 4A / 4B | B2B supplies, including reverse charge |
| 5 | B2C large — inter-state above the threshold |
| 6A | Exports, with and without payment of tax |
| 7 | B2C small, rate-wise and state-wise |
| 9B | Credit and debit notes |
| 12 | HSN-wise summary of outward supplies |
What causes a mismatch
A missing customer GSTIN
A B2B supply with no GSTIN cannot go in table 4 and your customer cannot claim credit. This is the single most common and most expensive error.
The wrong place of supply
It decides whether the supply is IGST or CGST plus SGST. Get it wrong and the tax is right in total but in the wrong hands.
Credit notes not linked
A credit note must reference the invoice it reverses. An unlinked one is a negative figure the portal cannot reconcile.
Missing or wrong HSN
Table 12 needs an HSN summary at the digit level your turnover requires, and a missing code stops the return.
B2C large in the wrong table
Inter-state B2C supplies above the threshold are reported invoice-wise, not in the consolidated table.
Amendments made as new entries
A correction to a previous period is an amendment against the original document, not a fresh invoice in the current one.
How to file cleanly
- Close the period. Stop anything new posting into a month you are about to report.
- Run the checks first. Missing GSTINs, missing HSN codes, unlinked credit notes and blank places of supply — fix these before you look at any figures.
- Read the tables. Reconcile the total of the return against your own sales register. If they differ, the return is not the thing to correct.
- Upload and file. Export the JSON, upload it on the portal, and file with your own credentials.
GSTR-1 questions
What is the most common cause of a GSTR-1 rejection?
A B2B invoice with no customer GSTIN, followed by missing HSN codes. Both are fixable in seconds on the invoice and impossible to fix in the return, which is why the check belongs before filing rather than during.
How do I correct an invoice from a previous period?
Through the amendment tables, against the original document, rather than by raising a new invoice in the current period. An amendment keeps the link; a fresh document breaks it and makes reconciliation harder for both sides.
Does GSTR-1 have to match my books exactly?
The return should reconcile to your sales register for the period. If it does not, the discrepancy is almost always a classification difference — a document in the wrong table — rather than a missing sale.
Is this page tax advice?
No. It is a practical summary; table numbers and thresholds change. Confirm with your tax adviser before relying on it.
Related
Run the readiness check first
tBiz lists every invoice that would be rejected before you go near the portal.