GSTR-1A explained: this guide covers what it means, who it applies to, the step-by-step process, documents required, fees, due dates and penalties in India — so you can stay compliant with confidence and avoid costly mistakes.
GSTR-1A is an optional form that lets you add a missed invoice or correct one already reported in GSTR-1, in the same tax period, provided you have not yet filed GSTR-3B. Used well, it keeps your GSTR-3B liability right and avoids the usual clean-up through the next month's amendment tables.
The proviso to Rule 59(1), inserted by Notification 12/2024-CT dated 10 July 2024, allows a registered person, after furnishing GSTR-1 for a tax period but before filing GSTR-3B for that period, to amend or add details in FORM GSTR-1A, at his own option. It can be filed only once per tax period. The net result flows into GSTR-3B for the same period, and the recipient's credit shows in GSTR-2B of the next tax period.
When the window is open
| Filer type | GSTR-1A opens | GSTR-1A closes |
|---|---|---|
| Monthly GSTR-1 | After the later of the due date and the actual filing date of GSTR-1 | When GSTR-3B for the same period is filed |
| Quarterly (QRMP) | After the later of the due date and the actual filing date of quarterly GSTR-1 | When GSTR-3B for the same quarter is filed |
The facility was made available from August 2024 for amending GSTR-1 details for July 2024 onwards. It is optional, it carries no late fee, and it can be filed once for a tax period. Once GSTR-3B is filed, the window is shut and later corrections go through the amendment tables of a subsequent GSTR-1, in line with section 37(3).
A linked point: a monthly filer cannot file GSTR-1 for a month until GSTR-3B for the preceding month is filed. So a slow GSTR-3B pushes every later month back. See sequential filing.
What you can put in GSTR-1A
Rule 59(4A) mirrors the contents of GSTR-1. As the requirement of the registered person demands, GSTR-1A may include:
- invoice-wise details of inter-State and intra-State supplies to registered persons;
- invoice-wise details of inter-State supplies to unregistered persons where the invoice value is more than Rs. 1 lakh;
- consolidated details of intra-State supplies to unregistered persons for each rate of tax, and of State-wise inter-State supplies up to Rs. 1 lakh;
- debit and credit notes issued during the month for earlier invoices.
The Rs. 1 lakh limit replaced Rs. 2.5 lakh with effect from 1 August 2024. If you prepare GSTR-1 yourself, a GSTR-1 filing review can make sure the first filing needs fewer corrections.
Worked example
Illustration: a monthly filer files GSTR-1 for October 2026 on 10 November 2026 and later realises a B2B invoice of Rs. 2,00,000 plus 18% GST (Rs. 36,000) was left out. GSTR-3B is due on 20 November.
- On 15 November he files GSTR-1A for October 2026 adding the invoice.
- GSTR-3B for October 2026 now auto-populates the output tax including the extra Rs. 36,000, so he pays it with the return.
- The buyer sees the invoice in GSTR-2B for November 2026, the next tax period, because the GSTR-1A details are reflected there. The Background Material says credit in respect of GSTR-1A reaches the recipient in the next period's GSTR-2B.
Had he missed the window and filed GSTR-3B first, he would have had to report the invoice in the next GSTR-1, pay the tax with interest, and the buyer's credit would wait as well.
How GSTR-1A fits with GSTR-3B and IMS
- Liability: the net of GSTR-1, any IFF and GSTR-1A populates GSTR-3B for the same period. Correct outward details before filing GSTR-3B also reduce the chance of an intimation under Rule 88C (DRC-01B) for a difference between GSTR-1 and GSTR-3B. See Rule 88C and DRC-01B.
- Recipients: Rule 60(7)(iia) brings GSTR-1A details into the buyer's GSTR-2B for the period in which GSTR-1A is filed after the previous period's GSTR-1 due date and up to the current GSTR-1 due date. Amended records in IMS are acted on after the original. See IMS accept, reject and pending.
- Wrongly rejected invoices: if a buyer rejects an invoice in IMS by mistake, the supplier can re-report the same record in GSTR-1A of the same period. The supplier's liability does not increase, because amendment entries take only the difference.
What GSTR-1A cannot do
- Recipient GSTIN: if the GSTIN of the recipient on a reported supply is wrong, it cannot be changed in GSTR-1A for the same period. It has to be corrected in GSTR-1 for the subsequent tax period.
- IFF entries under QRMP: invoices furnished through the Invoice Furnishing Facility for the first and second months of a quarter can only be amended through the quarterly GSTR-1A, not during those months.
- After GSTR-3B: the window is closed.
- Repeat use: one filing per tax period. Collect all corrections, then file.
Need help with GSTR-1 corrections?
Corrections are easiest when someone reviews the outward register against GSTR-1 before GSTR-3B is filed. Our team can do that check and prepare GSTR-1A where needed as part of GSTR-1 filing, and follow it through to the return. If a mismatch has already reached GSTR-3B, see GSTR-3B filing.
Key takeaways
- GSTR-1A is optional, carries no late fee and can be filed once per tax period.
- The window runs from GSTR-1 filing until GSTR-3B filing for the same period.
- It flows into the same period's GSTR-3B liability.
- The buyer's credit from GSTR-1A reaches GSTR-2B of the next tax period.
- A wrong recipient GSTIN cannot be fixed in GSTR-1A for the same period.
Read next
- Invoice Management System: accept, reject, pending
- GSTR-3B: auto-populated liability and hard-locking
- GSTR-1A: the amendment return and what it fixes
- Three-year time bar for filing GST returns
Disclaimer: Positions stated as on 30 September 2026, based on the CGST and IGST Acts and Rules as amended, the Finance Act 2026, and the ICAI Background Material on GST (14th Edition, July 2026). Verify current notifications before acting.