AY 2026-27 is the last Assessment Year under the Income Tax Act, 1961, and simultaneously the first year during which the Income Tax Act, 2025 is in force. This dual-law environment requires practitioners to carefully identify which Act governs each transaction.

Tax Year Concept Under the new Act, the dual-year system (earn in Previous Year, assess in Assessment Year) is replaced by a single Tax Year. Tax Year 2026-27 = April 1, 2026 to March 31, 2027. For AY 2026-27, however, the old terminology still applies: income of FY 2025-26 assessed in AY 2026-27.

The applicability thresholds for the mandatory tax audit under Section 44AB of the Income Tax Act, 1961 remain unchanged for AY 2026-27. The corresponding provision in the new Act is Section 63 of the Income Tax Act, 2025.

Section Renumbering Section 44AB of the Income Tax Act, 1961 has been renumbered as Section 63 under the Income Tax Act, 2025. The substantive thresholds and applicability conditions remain identical — this is a structural renumbering, not a policy change.

This is the most significant structural change in the audit ecosystem. The Ministry of Finance has introduced an entirely new audit reporting framework under the Income Tax Rules, 2026, but its applicability depends on the year of income.

For AY 2026-27 (FY 2025-26): Old Forms Continue

Upcoming: New Form 26 (from Tax Year 2026-27 onwards)

Under the Income Tax Act, 2025 and Income Tax Rules, 2026, Forms 3CA, 3CB, and 3CD will be consolidated into a single unified Form No. 26 governed by Section 63 of the new Act. This does not apply to AY 2026-27.

Form 26 Structure at a Glance The new Form 26 is organized into Parts A to D. Part A: general information and identification. Part B: tax-specific particulars with trigger-based schedules. Part C: audit opinion and observations. Part D: auditor certification with mandatory UDIN and Firm Registration Number.

Deadlines have seen significant revisions for AY 2026-27, with the government introducing staggered filing dates across taxpayer categories. Here is the complete timeline:

On 30 March 2026, the Ministry of Finance notified sweeping amendments to ITR Forms 1 through 7, ITR-V, ITR-Ack, and ITR-U — all effective 31 March 2026, applicable for returns filed for AY 2026-27.

The Finance Bill, 2026 has reshaped assessment and reassessment procedures that directly impact how audited taxpayers face scrutiny. These changes apply from Tax Year 2026-27.

Jurisdictional Reassessment Notices: Reassessment notices can now be issued only by the jurisdictional Assessing Officer, codified under Sections 280 and 281 of the Income Tax Act, 2025 (corresponding to Sections 148 and 148A of the 1961 Act). While proceedings remain faceless in execution, the power to initiate is now strictly jurisdictional.

Search-Related Block Assessments: The time limit for completing block assessments has been extended from 12 months to 18 months, applicable from Tax Year 2026-27 onwards, under Section 286 of the Income Tax Act, 2025.

DIN Requirements: A complete absence of Document Identification Number (DIN) coupled with no electronic audit trail may still be challenged in court, but minor DIN errors alone will no longer be sufficient grounds to invalidate proceedings.

A notable policy shift accompanies the AY 2026-27 audit regime: the amount payable on default of submitting the tax audit report has been converted from a "penalty" to "fees" — intended to reduce litigation by reframing the nature of the levy.

Reasonable Cause Defence No penalty/fee will be imposed under Section 271B if the taxpayer provides a reasonable cause for non-compliance, such as: (a) death or physical inability of the partner responsible for accounts; (b) loss of accounts due to theft, fire, or natural calamity; or (c) other genuine circumstances accepted by the Assessing Officer.

AY 2026-27 marks the intensification of convergence between Income Tax and GST compliance. Tax auditors are now expected to perform mandatory reconciliation between:

• Turnover reported in financial statements / Form 3CD
• Turnover figures reported in GST returns (GSTR-1, GSTR-3B)
• Data in the Annual Information Statement (AIS) and Form 26AS

Any material mismatch between these systems automatically heightens the taxpayer's risk profile and can trigger automated scrutiny notices. The era of siloed compliance is firmly over.

E-Invoicing Mandate: A strict 30-day time limit applies for reporting e-invoices, credit notes, and debit notes on the Invoice Registration Portal (IRP). This applies to taxpayers with an Annual Aggregate Turnover (AATO) of ₹10 crore and above — the same category subject to the enhanced ₹10 crore digital audit threshold under Section 44AB.

Clause 44 of Form 3CD — GST Breakup Reporting Clause 44 remains active for AY 2026-27 and requires a breakdown of all expenses into GST-registered and non-GST-registered categories. Auditors must ensure accurate population of this clause to avoid discrepancies auto-detected by the department's analytics engine.

EVC for Individual / HUF Authentication: Individual taxpayers and HUFs can now authenticate Form 3CB-3CD using the Electronic Verification Code (EVC), reducing the mandatory dependence on Digital Signature Certificates (DSCs).

While AY 2026-27 uses the old forms, practitioners should begin preparing for the landmark shift that kicks in for Tax Year 2026-27 (income earned from 1 April 2026 onwards):

• Single Unified Form 26 replaces Forms 3CA, 3CB, and 3CD — one form covers all audit cases regardless of whether accounts are audited under another law.
• UDIN is Mandatory — every Form 26 must carry the Unique Document Identification Number generated by the signing CA; no UDIN means invalid filing.
• FRN Required — where audit is conducted in the name of a firm, the Firm Registration Number must be quoted in Form 26.
• Technology Disclosure — mandatory reporting of accounting software used, cloud storage arrangements, and server locations to strengthen transparency.
• Trigger-Based Schedules — schedules required only when the corresponding clause is answered "Yes," making compliance proportionate to actual risk.
• Section References Change — all references in Form 26 correspond exclusively to the Income Tax Act, 2025 and Rules 2026. Old section numbers (like 44AB) must not be used.
• Due Date for Form 26 — 30 September 2027 (for Tax Year 2026-27), filed on the e-filing portal by the CA followed by taxpayer acceptance.
• Form 168 Replaces Form 26AS — the Annual Information Statement will be labelled by Tax Year (not Assessment Year) from Tax Year 2026-27 onwards.
• NPO Audit Forms — Forms 10B and 10BB for charitable trusts and NGOs are replaced by new forms under the Income Tax Rules, 2026.

A practical checklist for CAs and tax professionals managing audits for FY 2025-26:

• Confirm applicability of Section 44AB for each client based on current year turnover/gross receipts (thresholds: ₹1 Cr business, ₹10 Cr digital, ₹50 L profession).
• Use Form 3CA or 3CB (not Form 26) for all AY 2026-27 audits — Form 26 only applies from Tax Year 2026-27.
• Complete and file Form 3CD with all applicable clauses — particular attention to Clause 44 (GST breakup) and Clause 36B (share buyback).
• Reconcile turnover in Form 3CD with GST returns (GSTR-1, GSTR-3B) and AIS data before submitting the audit report — mismatches trigger automated notices.
• Verify e-invoicing compliance for clients with AATO above ₹10 crore (strict 30-day IRP reporting window).
• Generate and quote UDIN for all audit reports — ICAI requires UDIN even on the current Forms 3CA/3CB.
• Submit audit report by 30 September 2026; for transfer pricing cases, ensure completion by 31 October 2026.
• Advise clients on new filing deadlines: ITR-3/4 non-audit cases now have an extended deadline of 31 August 2026.
• Check ITR-U status — FY 2020-21 updated returns cannot be filed after 1 April 2026; revised additional tax rates apply for FY 2021-22 onwards.
• For individual/HUF clients, advise on option to authenticate Form 3CB-3CD via EVC instead of DSC.
• Begin transitioning practice systems and audit templates for Form 26 (new Act) ahead of Tax Year 2026-27 filing season (mid-2027).
• Reference the ICAI 2025 Guidance Note on Tax Audit under Section 44AB — the current authoritative guide for AY 2026-27 audits.