Tax Audit Under Section 44AB: Limits, Forms and Due Dates (2026-27)

What a tax audit actually is

A tax audit under Section 44AB is a verification exercise. A Chartered Accountant reviews your books, vouchers, ledgers, bank statements and GST returns, and certifies a statement of particulars about your income, turnover and deductions. It is not the same as a statutory audit, which is driven by your company structure. A tax audit is driven purely by your numbers, and it applies to proprietors, firms, LLPs and companies alike once they cross the threshold.

Importantly, the audit itself does not create a tax demand. It is a disclosure and verification step. But discrepancies it surfaces can trigger scrutiny later, which is exactly why getting it done accurately and on time matters.

Business thresholds and the 5% cash rule

For a business, the tax audit turnover limit is not a single line, it depends on how much of your money moves in cash:

The higher ₹10 crore threshold, introduced to reward digital transactions, has a strict condition: both your cash receipts and your cash payments must each stay under 5% of the total. If either side breaches 5%, you fall back to the ₹1 crore limit. This is why documenting your digital-receipt and digital-payment ratios matters, it is what defends the higher threshold if questioned.

Professionals and presumptive opt-outs

For professionals, the tax audit limit is ₹50 lakh in gross receipts, a much lower bar than for businesses. This covers the specified professions such as legal, medical, engineering, architectural, accountancy, technical consultancy, interior design and IT.

There is a second, separate trigger that catches people out: opting out of presumptive taxation. If you were under a presumptive scheme such as 44AD or 44ADA and you declare profits lower than the presumptive rate (while your income exceeds the basic exemption limit), a tax audit becomes mandatory regardless of your turnover, under Section 44AB(c), (d) or (e). Leaving the presumptive scheme is not a free decision, it can pull you straight into audit territory.

Forms 3CA, 3CB and 3CD, now Form 26

The tax audit report is filed on one of two forms, always accompanied by the detailed statement:

• Form 3CA is used when your accounts are already audited under another law, typically a company audited under the Companies Act, 2013.
• Form 3CB is used when no other audit applies and the tax-audit CA is your only auditor, typically proprietors, firms, HUFs and LLPs.
• Form 3CD is the detailed statement of particulars, a long clause-by-clause disclosure, filed with either 3CA or 3CB. For FY 2025-26 it carries revised disclosures, including Clause 22 on MSME payments.

How the audit is filed and accepted

The process has a step people forget, and forgetting it means the audit is treated as not filed:

• The CA reviews your books and prepares Form 3CD.
• The CA signs Form 3CA or 3CB digitally and uploads the report through their own login on the income tax e-filing portal.
• You must then accept the report from your own login, under Pending Actions. An audit report uploaded by the CA but not accepted by you is treated as not filed, and you are non-compliant with Section 44AB.
• Once accepted, the report auto-links to your ITR when you file it.

Due dates and the 271B penalty

For AY 2026-27 (FY 2025-26), the deadlines are:

• Tax audit report: 30 September 2026.
• ITR for audit-liable taxpayers: 31 October 2026.
• Transfer pricing cases (international or specified domestic transactions, Form 3CEB): 31 October 2026.

These are statutory dates. The CBDT has extended them in several recent years, but plan for the statutory date and treat any extension as a bonus, not a strategy.

Miss the deadline and Section 271B applies: 0.5% of total sales, turnover or gross receipts, capped at ₹1.5 lakh. Under recent changes this is being reframed as a fee rather than a penalty, but the amount still lands. Section 273B can waive it only where you prove reasonable cause, such as serious illness, a natural calamity, or the auditor's own delay, and that relief is not automatic.

Getting the applicability right, defending the ₹10 crore threshold, preparing 3CD accurately, and hitting the dates is precisely where a CA earns their place. Our audit and assurance service maps your facts to the correct sub-clause of Section 44AB and files on time.

Quick answers

When is a tax audit mandatory? Business turnover above ₹1 crore (or ₹10 crore if cash is under 5% of both receipts and payments), or professional gross receipts above ₹50 lakh, or opting out of presumptive taxation with lower declared profit. Which forms? 3CA or 3CB with 3CD, becoming Form 26 from Tax Year 2026-27. When is it due? Report by 30 September, ITR by 31 October. What is the penalty? 0.5% of turnover, capped at ₹1.5 lakh, under Section 271B. Need it handled? Our audit team does it end to end.