Annual Aggregate Turnover (AATO) Under GST: Meaning & Calculation

Annual Aggregate Turnover (AATO) Under GST: Meaning and How to Calculate It

Annual Aggregate Turnover, or AATO, is the number that decides whether your business needs GST registration, whether you qualify for the composition scheme, and whether e-invoicing or a GST audit applies to you. It's calculated at the PAN level, not per registration, which trips up a lot of businesses that operate across multiple states. Here's what goes into it and how to work it out for your own business.

Latest AATO Update: July 2026 Amendment Window

GSTN issued an advisory on 1 July 2026 shifting the annual AATO correction window. For years up to FY 2024-25, taxpayers could amend their AATO only during May. That's changed for FY 2025-26: the amendment window now runs from 1 July to 31 July 2026, with jurisdictional tax officers reviewing the amended data between 1 and 15 August 2026.

The shift ties into a bigger system upgrade. GSTN is rolling out functionality that automatically updates AATO as you file subsequent returns after the amendment window closes, instead of leaving it as a static figure taxpayers have to manually correct each year. Practically, this means accurate GSTR-1 and GSTR-3B filing throughout the year now matters more than ever, since your turnover figure will increasingly reflect what you've actually filed rather than what you amend once a year.

What Is Annual Aggregate Turnover Under GST?

AATO is your turnover for a full financial year, April to March, calculated across every GST registration you hold under a single PAN. Under GST law, aggregate turnover means the combined value of all taxable supplies, exempt supplies, exports, and inter-state supplies made by a person with the same PAN, computed on an all-India basis. Tax paid under Reverse Charge Mechanism on your inward supplies doesn't count toward this figure.

Why AATO Matters

Two compliance questions hinge directly on this number:

• Do you need to register for GST at all? A business crosses the mandatory registration threshold once its aggregate turnover exceeds ₹40 lakh (₹20 lakh for a smaller set of special category states). For service providers, the bar is lower: ₹20 lakh in normal category states, ₹10 lakh in special category states.
• Are you eligible for the composition scheme? This simplified, lower-compliance scheme has its own turnover ceiling, separate from the registration threshold.

What Counts Toward Your AATO

AATO is the sum of the following, added up across every GSTIN registered under your PAN:

• Taxable sales value
• Exempt sales value
• Value of goods and services exported
• Inter-state supplies made to a sister concern under the same PAN
• Inter-state stock transfers between distinct persons under the same PAN

A few rules govern what goes in and what stays out:

• Your taxable sales figure excludes RCM purchases, but sales on which you yourself are liable under RCM do get counted.
• CGST, SGST, UTGST, IGST, and cess are never part of the turnover figure. AATO is a measure of business activity, not tax collected.

How to Calculate AATO: Worked Examples

Example 1: Normal category state

Suppose a tea estate owner sells tea leaves worth ₹1.6 crore in a year, an activity exempt from GST. He also sells plastic packaging alongside his crop, billed separately, worth ₹5 lakh, which is taxable.

AATO = ₹1.6 crore + ₹5 lakh = ₹1.65 crore

Even though only ₹5 lakh of that is taxable turnover, GST registration becomes mandatory because the aggregate figure crosses the ₹40 lakh threshold. He also can't opt for the composition scheme, since ₹1.65 crore is well past that scheme's ceiling.

Example 2: Special category state

Now take a farmer in Nagaland who sells crops worth ₹25 lakh in a year, plus plastic bags worth ₹50,000.

AATO = ₹25 lakh + ₹50,000 = ₹25.5 lakh

Since Nagaland is a special category state with a ₹20 lakh threshold, registration is mandatory here too, despite the much smaller absolute turnover compared to the first example.

Special Category States and Their Thresholds

Not every state uses the same registration threshold. The ₹40 lakh limit that applies broadly has carve-outs:

Telangana also follows the ₹20 lakh threshold for goods, separate from this special category list.

AATO vs Turnover in State: They're Not the Same Thing

This distinction catches people out often enough to deserve its own section. AATO is calculated at the PAN level, across every state you operate in. Turnover in state is narrower: it's the turnover attributable to a single state or union territory.

Turnover in state includes taxable supplies (minus RCM inward supplies), exempt supplies made within that state, exports, and inter-state supplies made from that state. It excludes stock transfers and all the GST components (CGST, SGST, UTGST, IGST, cess), same as AATO.

The reason this distinction exists: composition scheme tax liability is calculated on turnover in state, not on your PAN-level AATO. A business with operations across several states pays composition tax separately, state by state, even though its eligibility for the scheme was determined by the PAN-level figure.

Where AATO Gets Used Across GST Compliance

Worth flagging on e-invoicing specifically: as of 2026, the mandatory threshold sits at ₹5 crore aggregate turnover, and it works on a "once crossed, always applicable" basis. If your turnover exceeded ₹5 crore in any year going back to FY 2017-18, e-invoicing applies to you now, even if your turnover has since dropped below that mark.

Frequently Asked Questions

What is the GST registration threshold for a normal category state? ₹40 lakh for goods and ₹20 lakh for services. Once your PAN-level aggregate turnover crosses this figure, registration is mandatory.

Is the AATO threshold the same for goods and services? No. Goods suppliers get a higher threshold (₹40 lakh in most states) compared to service providers (₹20 lakh in normal category states, ₹10 lakh in special category states).

Does exempt turnover count toward AATO? Yes. Exempt supplies are included in AATO even though they're not taxable, which is why a business dealing mostly in exempt goods can still cross the registration threshold.

Can I amend my AATO if it's showing incorrectly on the GST portal? Yes, during the designated amendment window. For FY 2025-26, that window runs from 1 to 31 July 2026, with tax officer review following from 1 to 15 August 2026.

Is turnover in state the same figure used for GST registration? No. Registration eligibility is based on PAN-level AATO across all states. Turnover in state is a narrower figure used specifically to calculate composition scheme tax liability.

What happens if I don't register even though my AATO crosses the threshold? Operating without mandatory GST registration exposes a business to penalties and interest on unpaid tax, along with the compliance risk of being flagged during any departmental review.

The Bottom Line

AATO is a PAN-level figure, not a per-registration one, and it drives more compliance decisions than most businesses realize: registration, composition scheme eligibility, e-invoicing, audit requirements, and return filing frequency all trace back to this number. Get your inclusions and exclusions right, keep an eye on your state's specific threshold, and use the amendment window if your GST portal figure doesn't match your actual books