GSTN Advisory No. 666: The FY 2025-26 AATO Amendment Window Closes July 31, 2026 (and GST Turnover Now Auto-Updates)
Quick Summary: GSTN Advisory No. 666 on AATO (FY 2025-26)
- What changed: By GSTN Advisory No. 666 dated 1 July 2026, the GST Network revised the timeline for amending your Aggregate Annual Turnover (AATO) for FY 2025-26 and deployed a new functionality that makes AATO update automatically as returns are filed.
- The window: The AATO amendment application window is open from 1 July to 31 July 2026. Tax officers review amendments from 1 August to 15 August 2026.
- The shift: The correction facility has moved from its earlier May slot (per the 2 May 2022 advisory) to this July-August window for FY 2025-26.
- Why it matters: Your AATO drives e-invoicing applicability, the 30-day e-invoice reporting rule, GSTR-9C reconciliation, and QRMP eligibility. A wrong AATO can wrongly switch these obligations on or off.
- Action by 31 July 2026: Check the AATO shown on your GST portal dashboard. If it is wrong, file the amendment before the window shuts, because after it closes the figure moves to auto-update mode.
Most businesses never think about the turnover figure sitting quietly on their GST portal dashboard, until it triggers an obligation they did not expect. The Aggregate Annual Turnover (AATO) is that figure, and it decides whether you must issue e-invoices, file a GSTR-9C reconciliation, or qualify for the quarterly QRMP scheme. In GSTN Advisory No. 666 dated 1 July 2026, the GST Network revised the AATO amendment window for FY 2025-26 and rolled out automatic turnover updation. This guide explains how to amend your GST AATO in the July 2026 window, what the new auto-update feature does, and why getting the number right before 31 July 2026 matters.
What does GSTN Advisory No. 666 actually change?
Two things. First, it revises the timeline for correcting your FY 2025-26 AATO. Second, it introduces a system upgrade so that AATO updates automatically as you file subsequent GST returns, rather than remaining frozen until a manual amendment window opens. GSTN has stated the change is intended to improve the consistency, accuracy and uniformity of AATO reporting across GST portal modules.
Historically, taxpayers could amend their AATO only during a short window each May, under the advisory dated 2 May 2022. For FY 2025-26, that facility has been shifted, and the corrected AATO now feeds an auto-updating figure going forward.
The FY 2025-26 AATO timeline you need to diarise
| Activity | Window | Who acts |
|---|---|---|
| AATO amendment application (FY 2025-26) | 1 July – 31 July 2026 | Taxpayer, on the GST portal |
| Tax officer review of amendments | 1 August – 15 August 2026 | Jurisdictional officer |
| Auto-update of AATO thereafter | On filing of subsequent returns | GST system (automatic) |
The practical takeaway: 31 July 2026 is your last day to push a manual correction for FY 2025-26 through the amendment route. Miss it, and you are relying on the system’s auto-computation, which you can influence only through the returns you file, not through a direct edit.
Why your AATO number is not just a statistic
AATO is a threshold trigger across the GST law. As the framework currently stands, the AATO slab your business falls into affects the following obligations. Confirm your exact slab, because thresholds are periodically revised:
| Obligation | AATO trigger (current position) | What it means |
|---|---|---|
| E-invoicing | AATO of Rs 5 crore or more in any financial year since 2017-18 | Mandatory generation of e-invoices with an IRN for B2B supplies |
| 30-day e-invoice reporting | AATO of Rs 10 crore or more | Invoices must be reported on the Invoice Registration Portal within 30 days |
| GSTR-9C reconciliation statement | AATO above Rs 5 crore | Self-certified reconciliation to be filed with the annual return |
| GSTR-9 annual return | Optional up to Rs 2 crore | Below the limit the annual return is optional |
| QRMP scheme | AATO up to Rs 5 crore | Quarterly return filing with monthly tax payment |
If your dashboard AATO is overstated, the portal may wrongly push you into e-invoicing or GSTR-9C when you are not liable. If it is understated, you may miss a mandatory obligation and face notices later. This is precisely why the July amendment window exists.
How to check and amend your AATO before 31 July 2026
- Log in to the GST portal and view the AATO displayed on your dashboard for FY 2025-26.
- Reconcile it against your books and your filed GSTR-1 and GSTR-3B for FY 2025-26. Aggregate turnover includes taxable, exempt, export and inter-state supplies computed on an all-India PAN basis, so verify the composition, not just the total.
- If the figure is correct, no action is needed; the system will auto-update it going forward.
- If the figure is wrong, file the amendment through the AATO functionality on the portal on or before 31 July 2026, with supporting workings.
- Track officer action during 1 to 15 August 2026, and respond to any query raised through the portal’s self-service facility.
- Keep your return filing clean thereafter, because from now on the AATO recomputes automatically from the returns you file.
This dashboard hygiene sits alongside the other GST changes reshaping FY 2026-27 compliance. See our guides on GSTR-3B hard-locking and the Invoice Management System, the deferral of mandatory Ship-To GSTIN on e-way bills, and who handles your GST case after a change of jurisdiction.
Frequently Asked Questions
What is the last date to amend AATO for FY 2025-26?
Per GSTN Advisory No. 666 dated 1 July 2026, the AATO amendment application window for FY 2025-26 is open from 1 July to 31 July 2026. The tax officer review runs from 1 to 15 August 2026.
What does the AATO auto-update feature do?
After the amendment window, the GST system automatically updates your AATO as you file subsequent returns, instead of holding the figure static until the next manual amendment cycle. It is designed to keep the turnover figure consistent across GST portal modules.
My AATO on the portal looks wrong. Will the auto-update fix it on its own?
Auto-update reflects the returns you file going forward; it does not retrospectively correct a wrong FY 2025-26 base figure. If the displayed AATO is incorrect, use the manual amendment window on or before 31 July 2026 rather than assuming the system will self-correct.
Does a lower AATO remove my e-invoicing obligation?
E-invoicing applicability is tested against the AATO of any financial year since 2017-18, not just the latest year. So once you have crossed the e-invoicing threshold in an earlier year, correcting a later year’s figure downward does not automatically switch off the obligation. Assess the full history before concluding.
Who should worry most about this window?
Businesses near a threshold boundary, for example around Rs 5 crore for e-invoicing and GSTR-9C, and those that had one-off spikes in turnover. For them, an inaccurate AATO can mean either an unnecessary compliance burden or a missed mandatory filing.
The bottom line for CAs and business owners
GSTN Advisory No. 666 is a small operational change with an outsized compliance footprint. The action is a five-minute dashboard check now, and a portal amendment before 31 July 2026 if the number is wrong. For CAs, this is worth a quick sweep across the client base: pull each GSTIN’s AATO, flag any that sit near an e-invoicing or GSTR-9C boundary, and correct the outliers while the window is still open. After 31 July, the figure runs on auto-pilot, and the easiest chance to set it right is gone.
Unsure which GST thresholds apply to your turnover?
Threshold-boundary businesses often get e-invoicing and annual-return obligations wrong, both ways. Schedule a Strategy Session with Tax Update India to review your AATO position and map exactly which GST obligations apply to you for FY 2026-27. Book a quick call and get clarity before the window closes.
Disclaimer: This article is for general information only and does not constitute legal, tax or professional advice. GST turnover thresholds and compliance obligations are revised from time to time; verify the current position against the GSTN advisory, the relevant CBIC notification and the CGST Act and Rules before acting. Consult a qualified professional for advice specific to your business.
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