Tax Audit Checklist FY 2025-26: The Last Year of Form 3CA, 3CB and 3CD

Every year, tax audit season in India follows the same pattern: books get finalised in a rush during the last two weeks of September, CAs work through weekends, and clients scramble for documents they should have organised in April. This year carries one more layer — it's the final tax audit conducted under the current Form 3CA, Form 3CB, and Form 3CD structure.

From Tax Year 2026-27 onward, under the Income-tax Act, 2025 and the Income-tax Rules, 2026, these three forms are being replaced by a single unified Form No. 26 under Section 63 of the new Act. Your audit for FY 2025-26 (Assessment Year 2026-27), however, is still governed entirely by the Income Tax Act, 1961, and still uses the existing forms. The tax audit report due date for this year remains 30 September 2026 under Section 44AB.

This guide walks through exactly what needs to be ready before your CA starts the audit, why each item matters, and what practicing CAs and CA students should be paying attention to for a clean, defensible audit file.

Who This Applies To

A tax audit under Section 44AB is mandatory if:

• Business turnover exceeds Rs 1 crore, or Rs 10 crore where cash receipts and cash payments are each within 5% of total turnover
• Professional gross receipts exceed Rs 50 lakh

Missing the deadline attracts a penalty under Section 271B: 0.5% of turnover, capped at Rs 1,50,000.

1. Books and Trial Balance

Close your books completely before handing them to your auditor. A trial balance that's still being adjusted while the audit is underway is the single biggest cause of last-minute errors and rushed sign-offs. Once the CA starts working from a set of numbers, changing them mid-audit means re-checking everything downstream — GST reconciliation, depreciation schedules, related party disclosures, all of it.

Practical tip: reconcile opening balances against last year's audited financials before you even start on the current year. A carried-forward mismatch is far easier to catch in April than in the last week of September.

2. Bank Reconciliation — Every Account, Not Just the Main One

It's common for businesses to reconcile their primary current account and forget the rest. Every account needs a 31 March 2026 reconciliation: current accounts, overdraft (OD), cash credit (CC), and term loan accounts. Unreconciled bank charges, unadjusted cheques, and unexplained credits are exactly what draws audit queries, and in many cases, income tax department scrutiny later.

3. GST Reconciliation — Books vs GSTR-1, 3B, and 2B

This is where a large share of audit observations originate. Your books' turnover needs to match:

• GSTR-1 — what you declared as outward supply
• GSTR-3B — your summary return and tax paid
• GSTR-2B — the input tax credit auto-populated based on your suppliers' filings

When these three don't align with your books, the mismatch has to be explained, not ignored. Common causes include invoices raised in one month but recorded in books in another, credit notes not reflected correctly, or ITC claimed on invoices that don't show up in 2B because a supplier filed late.

4. MSME Payment Compliance — Section 43B(h)

This clause has caught out more businesses in the last two years than almost any other. If you owe money to a supplier registered under the MSME (Udyam) framework:

• 45 days to pay, if there's a written agreement specifying the period
• 15 days to pay, if there's no such agreement

Miss this window, and the expense is disallowed for deduction in that year — permanently, not just deferred. Businesses that deal with a large number of small vendors should build a habit of checking Udyam registration status at the vendor onboarding stage, not at audit time when it's too late to change payment behaviour for the year already closed.

5. Cash Transaction Limits

Two separate provisions matter here, and they're often confused with each other:

• Section 40A(3) — cash payments above Rs 10,000 to a single person in a single day are disallowed as a business expense
• Section 269ST — cash receipts above Rs 2 lakh in aggregate from one person attract a penalty under Section 271DA equal to 100% of the amount received

Also check cash loans and deposits above Rs 20,000 against Sections 269SS and 269T — these carry their own penalty provisions and are frequently overlooked because they don't sit in the P&L, they sit on the balance sheet.

6. PF and ESI — Employees' Contribution

This is one area where the law draws a hard line with no flexibility. The employer's own contribution to PF and ESI follows Section 43B, meaning it can be paid up to the return filing due date and still claimed. The employees' contribution — the amount deducted from salary and held in trust to deposit — is different. If it's deposited even one day after the due date prescribed under the PF or ESI Act, the deduction is permanently lost under Section 36(1)(va). There is no relief under Section 43B for this specific item, regardless of when the return is filed.

7. Closing Stock

Prepare your stock statement item-wise and quantity-wise, with the valuation method clearly stated and consistently applied — cost, net realisable value, or the lower of the two, following applicable accounting standards. One check that's easy to skip: compare your closing stock figure in the books against the last stock statement submitted to your bank for CC or OD limits. A mismatch between the two is a red flag that both auditors and bankers notice.

8. Fixed Assets and Depreciation

Check the "put to use" date for every addition during the year. Assets used for fewer than 180 days in the financial year are only eligible for half the normal depreciation rate. This single rule is responsible for a large share of depreciation-related adjustments found during audits, usually because the addition date recorded in the books doesn't match when the asset was actually commissioned.

9. Related Party Transactions

List out every transaction with partners, directors, and relatives separately — salary, interest paid, rent, or any other payment. Section 40A(2) allows the assessing officer to disallow any part of such a payment considered excessive or unreasonable compared to fair market value. Document your basis for the rate or amount paid; "that's what we've always paid" is not documentation.

What This Means for CA Students and Beginners in Practice

If you're an articled assistant or a newly practicing CA handling your first few tax audits, a few things matter beyond the technical checklist itself:

• UDIN is not optional. Every tax audit report requires a Unique Document Identification Number generated before or at the time of upload. Reports without a valid UDIN are treated as invalid.
• Form 3CA vs Form 3CB is a factual question, not a judgment call. Use Form 3CA only where the entity's accounts are already required to be audited under another law — most commonly the Companies Act, for a company. Use Form 3CB for everyone else. Both come attached with Form 3CD.
• Working papers should map to Form 3CD clauses, not just to the trial balance. An audit file that only shows how you arrived at the numbers, without showing how each clause of Form 3CD was verified, is incomplete if it's ever reviewed.
• Get the engagement letter and management representation letter on file before you sign off, not after. These aren't formalities — they define the scope of what you were engaged to do and put client-provided information on record as client-provided.
• Start learning the Form 26 structure now, even though it doesn't apply this year. It consolidates 3CA, 3CB, and 3CD into one document with five parts and expands the total clause count. The transition year for your practice is next year, not this one — and the firms that start early won't be relearning the framework under deadline pressure in 2027.

Before 30 September

Treat this checklist as a working file, not a one-time read. Applicability of specific provisions depends on your turnover, cash transaction ratio, and entity structure — get that verified against your specific facts rather than assuming a generic answer applies.

If you want a second set of eyes on your tax audit readiness before the deadline, or you're unsure whether a specific transaction or payment falls foul of one of these provisions, get in touch with our team at Lawgical Station for a consultation.