Tax Audit Turnover Limits Explained: Are You Required to File by October 31?

AY 2026-27 Compliance Guide  |  6 min read

If your business or profession crossed a certain turnover this year, July 31 was never your deadline. October 31 is and missing it costs a lot more than a late fee.

Every year, a section of taxpayers assumes the regular ITR deadline applies to them, only to realise much later that their accounts needed a tax audit first. If your turnover or gross receipts crossed the prescribed threshold in FY 2025-26, you fall into that category and your compliance calendar looks completely different from a salaried employee's or a small trader's.

Here is exactly who needs a tax audit under Section 44AB, what the current turnover limits are, and what happens if you miss the October 31 deadline.

Who Actually Needs a Tax Audit?

A tax audit under Section 44AB is not applicable to every business owner or professional. It kicks in only once your turnover, gross receipts, or declared income crosses specific thresholds prescribed by the Income Tax Act. The idea is simple: once your financial scale crosses a certain point, the department wants a Chartered Accountant to certify your books before you file your return.

What About Presumptive Taxation?

If you are registered under Section 44AD (business) or Section 44ADA (professionals), you are generally exempt from a tax audit as long as you declare income at or above the prescribed presumptive rate (typically 8% or 6% of turnover for businesses, and 50% of gross receipts for professionals).

The audit obligation returns if you declare income below this presumptive rate and your total income exceeds the basic exemption limit. This is one of the most common traps: businesses that opted for presumptive taxation in earlier years, then reported a lower profit this year without realising it re-triggers the audit requirement.

The Compliance Calendar for AY 2026-27

Note that the audit report and the ITR are two separate filings. Your CA uploads the audit report first, you accept it on the income tax portal, and only then can your ITR reflect the audited figures. Leaving this too close to October 31 is the single biggest reason audit-case taxpayers end up filing late.

What Happens If You Miss It?

• Penalty under Section 271B: 0.5% of your turnover or gross receipts, capped at ₹1,50,000  even if the delay is by a single day, unless you can show reasonable cause.
• Return becomes defective: Filing your ITR without the required audit report attached can render the return defective under Section 139(9).
• Loss of carry-forward benefits: A defective or late return can affect your ability to carry forward business losses to future years.
• Interest under Section 234A: Continues to accrue at 1% per month on any outstanding tax liability from the original due date.

What You Should Do Right Now

If your turnover or receipts are anywhere close to these thresholds, do not wait for your CA to bring it up. Get your books reconciled, confirm whether you fall under audit, and start the process well before September 30 the ITR deadline of October 31 depends entirely on the audit report being filed first.