GST Update | GSTN Advisory 666 | AATO Amendment
GSTN Advisory 666: Revised AATO Amendment Timeline for FY 2025-26
GSTN has issued Advisory No. 666 dated 1 July 2026 revising the timeline for amendment of Aggregate Annual Turnover, or AATO, for FY 2025-26.
The AATO amendment facility for FY 2025-26 will now be available on the GST Portal from 1 July to 31 July 2026. The amended details will be available for review by jurisdictional Tax Officers from 1 August to 15 August 2026.
Read Official GSTN AdvisoryWhat has changed under GSTN Advisory 666?
GSTN has revised the AATO amendment timeline for FY 2025-26. Taxpayers can submit an AATO amendment application from 1 July to 31 July 2026.
Jurisdictional Tax Officers will review the amended AATO details from 1 August to 15 August 2026. The revision is linked with GSTN’s system upgrade for automatic updation of AATO as subsequent returns are filed after the amendment window.
Table of Contents
Revised AATO Amendment Timeline for FY 2025-26
Taxpayers should complete their review and amendment, wherever required, within the revised July 2026 window.
| Activity | Revised Timeline |
|---|---|
| AATO Amendment Application window for FY 2025-26 | 1 July to 31 July 2026 |
| Review by jurisdictional Tax Officer | 1 August to 15 August 2026 |
Why has GSTN revised the AATO amendment timeline?
GSTN has stated that the AATO functionality is being upgraded to enable automatic updation of Aggregate Annual Turnover as subsequent returns are filed after the amendment window.
The system-level enhancements are being implemented to improve consistency, accuracy and uniformity in the reporting of AATO across various modules of the GST Portal.
Practical meaning: Taxpayers should not treat the AATO amendment window as a routine portal formality. The displayed AATO should be compared with relevant records before submitting any amendment.
Earlier Process vs FY 2025-26 Process
GSTN had earlier issued an advisory dated 2 May 2022 regarding the functionality for amendment of Aggregate Annual Turnover on the GST Portal. Under the earlier process, taxpayers were provided the facility to amend their turnover during May, applicable up to FY 2024-25.
Earlier Process
The AATO amendment facility was made available during May as per the previous advisory process.
FY 2025-26 Process
For FY 2025-26, the amendment window has been revised to 1 July to 31 July 2026.
What should taxpayers do?
Taxpayers should log in to the GST Portal and carefully verify the AATO details displayed for FY 2025-26. An amendment should be submitted only where the displayed amount requires correction.
Compare turnover records
Compare the displayed AATO with relevant return data, books and turnover workings.
Verify the financial year
Check whether the amount relates correctly to FY 2025-26 before taking action.
Review before submission
Verify the amended amount carefully before final submission on the GST Portal.
Keep supporting records
Retain appropriate turnover workings and supporting records for future reference.
Where the displayed AATO is correct, taxpayers should avoid making an unnecessary amendment.
Important Point for CAs and GST Professionals
CAs, GST practitioners and compliance teams handling multiple clients should identify taxpayers for whom AATO details require review.
A simple client-wise review tracker can help professionals complete this process before the amendment window closes.
Suggested Client Review Tracker Fields
- GSTIN
- FY 2025-26 turnover as per available records
- AATO displayed on the GST Portal
- Whether amendment is required
- Date of amendment submission
- Supporting working or review note
Any interpretation concerning a taxpayer’s turnover computation or eligibility should be reviewed based on applicable GST provisions and the taxpayer’s own records.
What if a taxpayer faces a portal difficulty?
Where a taxpayer faces a technical difficulty or has a concern regarding the AATO amendment facility, GSTN has advised raising a grievance through the Self-Service Portal available on the GST Portal.
Keep grievance details complete
The grievance should include relevant information and supporting details so that the issue can be examined effectively. Taxpayers should retain the grievance reference number and supporting screenshots for follow-up.
TaxPower GST Practical Note
TaxPower GST users should compare the relevant turnover records and GST return data available in their system with the AATO displayed on the GST Portal before submitting an amendment.
The final AATO amendment is carried out on the GST Portal. Taxpayers and professionals should verify the applicable turnover position and supporting records before submission.
Contact TaxPower GST SupportFAQs on GSTN Advisory 666 and AATO Amendment
1. What is GSTN Advisory 666 about?
GSTN Advisory 666 dated 1 July 2026 revises the timeline for amendment of Aggregate Annual Turnover for FY 2025-26 on the GST Portal.
2. What is the AATO amendment window for FY 2025-26?
The AATO amendment application window for taxpayers is from 1 July to 31 July 2026.
3. When will Tax Officers review amended AATO details?
Jurisdictional Tax Officers will review amended AATO details from 1 August to 15 August 2026.
4. Was the AATO amendment facility previously available in May?
Yes. Under the earlier process applicable up to FY 2024-25, the amendment facility was available during May. For FY 2025-26, the window has been shifted to July 2026.
5. Why has GSTN changed the AATO amendment timeline?
GSTN is upgrading the functionality to enable automatic updation of AATO as subsequent returns are filed after the amendment window and to improve consistency and accuracy across GST Portal modules.
6. Should every taxpayer amend the displayed AATO?
No. Taxpayers should first verify the AATO displayed on the portal. An amendment should be submitted only where the displayed amount requires correction.
7. What should a taxpayer do if the AATO facility is not working properly?
The taxpayer should raise a grievance through the Self-Service Portal available on the GST Portal and provide all relevant details and supporting information.
Final Note
This article is based on GSTN Advisory No. 666 dated 1 July 2026 concerning the revised timeline for amendment of AATO for FY 2025-26.
Taxpayers should refer to the official GSTN advisory and verify their turnover records carefully before submitting an amendment.
This article is intended for general information and practical preparedness. It should not be treated as a legal opinion or as a substitute for professional review of a taxpayer’s specific turnover position.
Official reference: GSTN Advisory No. 666 dated 1 July 2026
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