GSTR-1A is an optional facility that lets you amend or add records to your GSTR-1 for the same tax period after filing it but before filing GSTR-3B. It ensures corrections flow into your GSTR-3B liability correctly, so you can fix a wrong value, a missed invoice, or a GSTIN without waiting for the next period.
Form GSTR-1A allows registered taxpayers to modify sales invoice details originally declared in GSTR-1 for the same tax period, before filing GSTR-3B. Reintroduced in July 2024 through CBIC Notification No. 12/2024, this form enables corrections to errors and additions of missed transactions without waiting for the next period’s amendment cycle.
What Is GSTR-1A?
Form GSTR-1A permits a registered taxpayer to update previously submitted sales data in GSTR-1 within the same tax period. Any error in a GSTR-1 transaction can be corrected, or a missed transaction can be added, through GSTR-1A for that period. The form does not allow changes to the recipient’s GSTIN.
For example, if a taxpayer files GSTR-1 for May 2025 on June 10, 2025, and discovers errors, GSTR-1A becomes active on June 11, 2025. The taxpayer can then amend or add details until GSTR-3B for May 2025 is filed on June 20, 2025. The corrected values are automatically reflected in GSTR-3B.
This form was originally part of the GST return filing framework but was suspended shortly after GST’s introduction in 2017. CBIC Notification No. 12/2024, dated July 10, 2024, reintroduced GSTR-1A by adding a proviso to Rule 59(1) of the CGST Rules.
Latest Updates on GSTR-1A
Hard-locking of GSTR-3B (from July 2025). The GSTN announced that auto-filled sales liability data in Table 3 of GSTR-3B will be hard-locked from the July 2025 tax period onward. Taxpayers will no longer be able to manually adjust values auto-populated from GSTR-1, GSTR-1A, or IFF. Suppliers must promptly use GSTR-1A to correct any documents that B2B purchasers reject through the Invoice Management System (IMS).
Three-year filing deadline. A new GSTN advisory imposes a restriction: taxpayers cannot submit GSTR-1, GSTR-3B, GSTR-4, GSTR-5, GSTR-5A, GSTR-6, GSTR-7, GSTR-8, and GSTR-9 returns more than three years after their respective due dates. This takes effect from the July 2025 tax period.
HSN Code Phase III (from April 2025). Table 12 of GSTR-1 and GSTR-1A now requires separate HSN-wise classification for B2B and B2C supplies. Manual HSN entry is no longer permitted. Taxpayers must select HSN codes from a dropdown menu, and downward amendments must use a minus sign for differential amounts.
How Is GSTR-1A Different from GSTR-1?
GSTR-1 is the primary return for reporting all outward supply details, filed by the selling taxpayer. Data from GSTR-1 flows into the buyer’s GSTR-2B for Input Tax Credit purposes.
GSTR-1A is specifically designed for amendments to GSTR-1 details within the same month. While GSTR-1 captures the original supply data, GSTR-1A captures corrections and additions. The ITC associated with amendments made through GSTR-1A becomes available to recipients in the GSTR-2B of the subsequent tax period.
Consider this example: Vijay Wholesale Stationery mistakenly records a sale of Rs. 5,000 as Rs. 500 in GSTR-1 for May 2025. This incorrect data appears in the buyer Ajay’s GSTR-2B. Vijay corrects the amount to Rs. 5,000 using GSTR-1A for May 2025. Ajay’s GSTR-2B for June 2025 then reflects this correction, and Vijay’s GSTR-3B is also updated.
When Can GSTR-1A Be Filed?
GSTR-1A becomes active after the later of the filing date or the due date of GSTR-1 (whether monthly or quarterly). It can be filed at any point before the submission of GSTR-3B for the same tax period. Only one GSTR-1A can be filed per tax period.
GSTR-1A Filing Timeline
| Event | Timeline |
| GSTR-1 filed, or due date passed | GSTR-1A becomes active the next day |
| GSTR-1A filing window | From the day after GSTR-1 filing until GSTR-3B is filed |
| GSTR-1A filing limit | Once per tax period |
| ITC impact on the recipient | Reflected in the next period’s GSTR-2B |
| Hard-locking of GSTR-3B | Effective from the July 2025 tax period |
Structure of GSTR-1A
The updated GSTR-1A format comprises 15 tables covering all categories of supply amendments:
Tables 1 to 3 capture basic details, including GSTIN, taxpayer name, and the Application Reference Number (ARN) auto-populated by the system.
Table 4 covers amendments to taxable outward supplies for registered persons, including standard sales invoices and reverse-charge invoices.
Table 5 records rate-wise inter-state outward supplies to unregistered persons where invoice value exceeds Rs. 1 lakh, including e-commerce operator supplies.
Table 6 addresses amendments concerning exports, supplies to SEZ units or developers, and deemed exports.
Table 7 captures changes in consolidated rate-wise intra-state and inter-state supplies up to Rs. 1 lakh to unregistered persons. If a place of supply with a specific GST rate combination was already declared in GSTR-1, new rates cannot be added via Table 7. The amendment facility in Table 10 must be used instead.
Table 8 records adjustments to nil-rated, exempted, and non-GST outward supplies made to both registered and unregistered persons.
Tables 9 and 10 handle amendments to previously reported taxable outward supply details from GSTR-1 Tables 4, 5, 6, and 7.
Table 11 covers advances received for which invoices are pending, advances adjusted against supplies, and revisions to previously reported advance data.
Table 12 captures HSN-wise summary modifications. From April 2025, this requires separate B2B and B2C tabs with dropdown HSN code selection.
Tables 13 to 15A record amendments related to e-commerce operator supplies, including supplier reporting and operator reporting for both registered and unregistered recipients.
Key Compliance Considerations
| Consideration | Details |
| GSTIN amendment | Not permitted through GSTR-1A. |
| Registration risk | Excess sales in GSTR-1 plus GSTR-1A over GSTR-3B may trigger cancellation under Rule 21(f). |
| HSN code entry | Dropdown selection only from January 2025. |
| B2B Table 12 | Cannot be left blank if B2B supplies are reported in other GSTR-1 sections. |
| Phase III validations | Currently in warning mode; taxpayers receive alerts but can still file. |
For further details on various return types, deadlines, and filing frequencies, refer to the GST Returns.
Are You Using GSTR-1A to Correct Filing Errors?
Timely amendments through GSTR-1A prevent mismatches in GSTR-3B and protect your recipients’ ITC claims. Use WFYI tools to track amendment deadlines and reconcile your supply data.
| Disclaimer: This article is for informational purposes only and does not constitute legal or tax advice. Consult a qualified tax professional for advice specific to your situation. |
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Frequently Asked Questions
Q1: What is the purpose of Form GSTR-1A?
GSTR-1A allows taxpayers to amend or add details to their already filed GSTR-1 for the same tax period, before filing GSTR-3B. It corrects errors and adds missed transactions without waiting for the next period’s amendment cycle.
Q2: Can GSTR-1A be used to change the recipient’s GSTIN?
No. GSTR-1A does not permit changes to the recipient’s GSTIN. If an incorrect GSTIN was reported, the original invoice must be amended through the subsequent period’s GSTR-1 amendment section.
Q3: How many times can GSTR-1A be filed in a single tax period?
GSTR-1A can be filed only once per tax period. Taxpayers must ensure that all corrections and additions are included in a single filing before submitting GSTR-3 B.
Q4: What happens to ITC when a supplier files GSTR-1A?
The Input Tax Credit associated with amendments made through GSTR-1A becomes available to the recipient in the GSTR-2B of the subsequent tax period, not the current period.
Q5: What is the impact of GSTR-3B hard-locking from July 2025?
From July 2025, taxpayers will not be able to manually adjust auto-populated sales liability values in Table 3 of GSTR-3B. All corrections must be made through GSTR-1A before filing GSTR-3B, making timely use of this form critical.
Frequently Asked Questions (FAQ)
What is GSTR-1A?
GSTR-1A is an optional statement that lets you amend or add records to a GSTR-1 you have already filed for the same tax period, before you file GSTR-3B.
When can I file GSTR-1A?
You can file GSTR-1A after submitting GSTR-1 for a period and before filing the GSTR-3B for that same period.
Is GSTR-1A mandatory?
No. GSTR-1A is optional; you use it only when you need to correct or add details to a GSTR-1 already filed.
Why should I use GSTR-1A?
It lets you fix errors in GSTR-1, such as a wrong invoice value or GSTIN, so that your GSTR-3B liability auto-populates correctly for the same period.
