GST Audit Checklist 2026: Documents & Compliance Requirements
GSTR-9 annual return is mandatory for all registered taxpayers. GSTR-9C audit applies to businesses above ₹5 crore turnover. Here is everything you need to prepare for GST audit — documents, reconciliation steps, and common red flags.
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Key takeaways
- GSTR-9 is due December 31 for turnover above Rs 2 crore; GSTR-9C adds a CA-certified reconciliation above Rs 5 crore.
- GSTR-9 has 19 tables in 6 parts; Part IV lets you declare correct figures from audited books and pay shortfalls via DRC-03.
- Late GSTR-9 costs Rs 200 per day, capped at 0.25% of turnover, plus a possible Section 125 penalty up to Rs 25,000.
- The biggest audit red flags are GSTR-1 vs GSTR-3B mismatches, ITC above GSTR-2B, unreversed blocked credits and unpaid RCM.
GST Audit in India: The Two Types Every Business Should Know
In the context of GST, 'audit' means two different things. First, the annual self-reconciliation through GSTR-9 and GSTR-9C that every registered taxpayer must file. Second, a field audit initiated by GST authorities under Section 65 or Section 66 of the CGST Act, where a tax officer examines your records physically.
This guide covers both — but focuses primarily on the self-audit compliance through GSTR-9 and GSTR-9C, since that is what most businesses face annually. If you are subject to a departmental GST audit, the same document checklist applies, but with stricter timelines and an authorized officer examining your records.
GSTR-9 (Annual Return): Mandatory for all GST-registered taxpayers with turnover above Rs 2 crore. Due December 31 each year for the previous financial year. Summarizes all 12 months of outward supplies, inward supplies, and ITC.
GSTR-9C (Reconciliation Statement): Mandatory only for taxpayers with aggregate turnover above Rs 5 crore. Must be certified by a Chartered Accountant or Cost Accountant. Reconciles GSTR-9 data with audited financial statements.
Preparing for either type of audit requires organized records. Use our GST calculator to verify tax amounts during reconciliation, and use myBillPlease to pull all your invoice data in one export for audit preparation.
Documents Required for GST Audit: The Master List
Assemble these documents before your CA begins GSTR-9C preparation or before a departmental audit visit
- GSTR-1 filed returns for all 12 months of the financial year (download from GST portal)
- GSTR-3B filed returns for all 12 months (download from GST portal)
- GSTR-2B for all 12 months (auto-populated inward supplies — download from GST portal)
- All sales invoices, debit notes, and credit notes issued during the year
- All purchase invoices and expense bills on which ITC was claimed
- Books of accounts — ledger, cash book, bank statements for the full year
- Audited financial statements (P&L and Balance Sheet) certified by your statutory auditor
- Stock register — opening stock, purchases, sales, closing stock for the year
- E-way bill register showing all e-way bills generated and cancelled during the year
- LUT or bond filed if you are an exporter
- Export invoices, shipping bills, and FIRCs/BRCs (for service exporters)
- HSN-wise summary of outward supplies (Table 17 of GSTR-9)
- ITC register showing month-wise ITC claimed, ITC reversed, and net ITC
- All RCM invoices and self-invoices (if you received supplies under reverse charge)
- Advance received and advance adjusted register (if you received advances against supply)
- E-invoices with IRN details if you are covered by e-invoicing (turnover above Rs 5 crore)
- Pending refund applications (if any) with status
- Any demand notices, show-cause notices, or orders from GST department during the year
GSTR-9 Annual Return: Table-by-Table Guide
GSTR-9 has 19 tables organized into 6 parts. Understanding each part helps you prepare the data correctly and avoid mismatches.
Part I (Tables 1-3): Basic Details
Your GSTIN, legal name, trade name, and the financial year. Auto-populated — no data entry needed.
Part II (Tables 4-5): Outward and Inward Supplies Declared in Regular Returns
Tables 4A-4I: Total outward supplies — taxable, zero-rated, nil-rated, and exempt. This must match the aggregate of all your GSTR-1 filings for the year.
Table 5: Outward supplies on which tax is not payable — exemptions, nil-rated, and non-GST supplies.
Part III (Tables 6-8): ITC Declared in Regular Returns
Table 6: Total ITC claimed across all 12 GSTR-3B returns, broken down by inputs, input services, and capital goods.
Table 7: ITC reversed and ineligible ITC (Section 17(5), Rule 42/43 reversals).
Table 8: ITC comparison — what you claimed vs. what was available in GSTR-2B. This is often where discrepancies surface.
Part IV (Tables 9-14): Declarations from Audited Accounts
This is the core of GSTR-9 — declare your outward supplies and ITC as per your audited books. If your GSTR-1 and GSTR-3B have gaps, errors, or omissions, report the correct figures here and pay any additional tax. This section allows you to correct underpaid taxes without paying a penalty (only interest applies if tax was short-paid).
Part V (Tables 15-16): Particulars of Transactions Relating to Previous FY
Table 15: Credit notes and amendments relating to the previous year but reported in the current year's returns.
Table 16: Supplies/tax declared in the current year but relating to the previous year (transition items).
Part VI (Tables 17-19): HSN Details and Late Fee
Table 17: HSN-wise summary of outward supplies — required for all taxpayers from FY 2025-26 onwards.
Table 18: HSN-wise summary of inward supplies — required for all taxpayers.
Table 19: Late fee payable if GSTR-9 is filed after December 31.
GSTR-9 vs GSTR-9C: Who Files What
Turnover determines your annual return obligations
| Criteria | GSTR-9 Only | GSTR-9 + GSTR-9C |
|---|---|---|
| Turnover threshold | Rs 2 crore to Rs 5 crore | Above Rs 5 crore |
| Who prepares | Taxpayer or their CA | Must be certified by CA or CMA |
| What it covers | Annual summary of supplies and ITC from regular returns | Same as GSTR-9 plus reconciliation with audited P&L |
| Key reconciliation | GSTR-1 vs GSTR-3B vs books | GSTR-9 vs audited financial statements — all differences explained |
| Due date | December 31 (for previous FY) | December 31 (for previous FY) |
| Late fee | Rs 200 per day (Rs 100 CGST + Rs 100 SGST), max 0.25% of turnover | Rs 200 per day, max 0.25% of turnover |
| Consequence of not filing | Section 125 penalty up to Rs 25,000 | Section 125 penalty; CA's certificate required, so additional professional cost |
Top 10 GST Audit Red Flags — and How to Address Them
These are the most common issues that surface during GSTR-9 preparation and departmental audits. Address each before your annual return filing:
1. GSTR-1 vs GSTR-3B mismatch: If your total taxable turnover declared in GSTR-1 (output tax return) differs from GSTR-3B (payment return) for any month, it creates a mismatch visible to GST authorities in their analytics. Always reconcile GSTR-1 and GSTR-3B totals monthly. Differences are reported in Table 9 of GSTR-9.
2. Excess ITC claimed vs GSTR-2B: Under the current rules, ITC cannot exceed the amounts in GSTR-2B. If your total ITC claimed in GSTR-3B across 12 months exceeds your GSTR-2B, the excess must be reversed with interest. Table 8 of GSTR-9 shows this comparison automatically.
3. ITC not reversed on ineligible inputs: Common items where ITC is often wrongly claimed and not reversed: company cars, directors' meals, employee canteen food, construction costs, and health insurance premiums. Reverse all blocked credits before filing GSTR-9.
4. Inter-unit transactions not declared: Businesses with multiple GST registrations (different states) must declare inter-branch stock transfers as taxable supplies. Stock transferred to another GSTIN without invoicing is a common audit issue.
5. Advance received — GST not paid: GST is payable on advances received for supply of goods and services, at the time of receipt. If you received advances and paid GST only when the invoice was raised, there is a timing mismatch that needs to be reconciled.
6. Export claims without shipping bill: If you claimed zero-rated export benefits but cannot produce shipping bills matching your GSTR-1 export invoices, the exports may be treated as domestic supplies and full IGST may be demanded.
7. RCM not paid on eligible transactions: Companies that receive services from unregistered vendors or specific notified services (GTA, legal services, security services) must pay GST under reverse charge. Unpaid RCM amounts surface during audit examination of your purchase ledger.
8. HSN code errors: Wrong HSN codes — either incorrect category or digit count — appear in Table 17 of GSTR-9 and can attract penalty of Rs 50 per invoice under Section 125.
9. Turnover underreported: GST on all taxable supplies including advances, free samples above threshold, and related party transactions at market value must be included in turnover. Omissions are a primary focus of department audits.
10. ITC on capital goods not tracked for multi-year reversal: ITC on capital goods (machinery, equipment, vehicles) is claimed in the year of purchase but must be tracked for 5 years. If the capital good is sold, transferred, or destroyed within 5 years, proportional ITC reversal is required under Rule 44.
If You Receive a GST Audit Notice Under Section 65
A Section 65 GST audit is conducted by a tax officer at your principal place of business. If you receive an audit notice, here is what to expect and how to prepare:
Notice period: You must receive at least 15 working days' notice before the audit begins. The notice specifies the financial year being audited and the records to be produced.
Duration: An audit must be completed within 3 months from the start date. This can be extended by 6 months by the Commissioner for complex cases.
Documents typically examined: Sales invoices, purchase invoices, stock registers, bank statements, financial statements, tax payment challans, GSTR-1 and GSTR-3B printouts, and any correspondence with GST department.
Your rights during audit: You can seek clarifications, point out legal positions, and request time to produce additional documents. You are entitled to a copy of the audit report. Before any demand is raised, a show-cause notice must be issued giving you an opportunity to respond.
Post-audit: If the auditor finds discrepancies, you will first receive a communication asking for your response. Voluntary payment of any tax shortfall discovered before a demand notice is raised is treated more favorably — it reduces the penalty exposure from 100% to nil in many cases under Section 73/74 of the CGST Act.
Maintaining organized records throughout the year in myBillPlease means your audit preparation reduces to pulling reports rather than reconstructing records. Every invoice, credit note, and ITC entry is timestamped and audit-ready from day one.
Frequently asked questions
- Who is required to file GSTR-9C (GST audit reconciliation statement) for FY 2025-26?
- GSTR-9C is mandatory for GST-registered taxpayers whose aggregate annual turnover exceeds Rs 5 crore in FY 2025-26. The statement must be prepared and certified by a Chartered Accountant or Cost and Management Accountant. It reconciles the data in GSTR-9 (annual return) with the audited financial statements — any differences between GST returns and books of accounts must be explained and additional tax, if any, must be paid. Businesses below Rs 5 crore only file GSTR-9 without the CA-certified reconciliation statement.
- What is the due date for filing GSTR-9 for FY 2025-26?
- GSTR-9 for FY 2025-26 is typically due December 31, 2026. CBIC has historically granted extensions for GSTR-9 and GSTR-9C — in some years extending to February 28 of the following year. The late fee for filing GSTR-9 after the due date is Rs 200 per day (Rs 100 CGST + Rs 100 SGST), subject to a maximum of 0.25% of the taxpayer's turnover in the relevant financial year. Monitor official CBIC notifications for any extensions applicable to FY 2025-26 annual returns.
- What happens if there is a difference between GSTR-9 and GSTR-3B?
- Differences between GSTR-9 and your monthly GSTR-3B filings are reported in Part IV of GSTR-9. If your annual return shows higher turnover or lower ITC than what was declared in monthly returns, the additional tax must be paid in DRC-03 along with 18% per annum interest calculated from the month the tax was originally due. Penalties may apply if the difference is due to fraud or willful misstatement. If the difference shows you overpaid tax in monthly returns, you can claim a refund. Timely reconciliation before filing annual return ensures the differences are minimized.
- Can I correct errors in GSTR-1 and GSTR-3B through GSTR-9?
- GSTR-9 allows you to report the correct figures from your books even if they differ from what you declared in monthly returns. You can declare additional outward supplies not reported in GSTR-1, claim unclaimed ITC (subject to eligibility and the September deadline), and declare ITC reversals not done in monthly returns. However, GSTR-9 itself is not an amendment mechanism for prior returns — it is a reconciliation declaration. Additional tax from GSTR-9 disclosures must be paid via DRC-03. ITC already lapsed (past the September cutoff) cannot be claimed through GSTR-9.
- What documents are checked first during a GST departmental audit?
- During a Section 65 GST departmental audit, the first documents typically examined are: your sales register (compared against GSTR-1 filed returns), purchase register (compared against GSTR-2B and ITC claimed in GSTR-3B), bank statements (for unrecorded credits that suggest unreported turnover), stock register (for unexplained variations), and your audited financial statements. Auditors specifically look for turnover in P&L that does not appear in GST returns, high ITC claims relative to output tax, and industries known for cash transactions where unreported income is common.
- What is the penalty for not filing GSTR-9?
- The late fee for not filing GSTR-9 by the due date is Rs 200 per day (Rs 100 CGST + Rs 100 SGST) for every day of delay, subject to a maximum of 0.25% of turnover in the relevant state. Additionally, under Section 125 of the CGST Act, a general penalty of up to Rs 25,000 may apply for contravention of GST provisions where a specific penalty is not prescribed. CBIC frequently issues late fee waivers and amnesty schemes for GSTR-9, so check for any applicable notifications before paying late fees.
- Is GSTR-9 mandatory for businesses with turnover below Rs 2 crore?
- No. CBIC has consistently exempted taxpayers with aggregate annual turnover of Rs 2 crore or below from filing GSTR-9. This exemption is typically notified each year — for FY 2025-26, the expectation is that the Rs 2 crore exemption will continue, but confirm with the official CBIC notification when filing for FY 2025-26. Even if exempt from GSTR-9, monthly GSTR-1 and GSTR-3B obligations continue as usual. Composition scheme dealers file GSTR-4 (annual) instead of GSTR-9.
