GST Audit in India — GSTR-9C, Internal Review & Departmental Audit

GST Audit is the examination of a taxpayer's GST records, accounts, and returns to verify that the GST liability has been correctly computed and paid, and that the Input Tax Credit (ITC) claimed is eligible and accurately stated. With the GST department increasingly using data analytics and AI to identify mismatches and anomalies, a proactive GST audit by a Chartered Accountant — before the department comes calling — is one of the most valuable compliance investments a business can make. This guide explains GST audit in India comprehensively.

1. What is GST Audit?

GST Audit refers to the examination of records, returns, and other documents maintained by a registered GST taxpayer to verify the correctness of the turnover declared, taxes paid, refund claimed, and input tax credit (ITC) availed. There are two distinct types of GST audit in India:

• Departmental GST Audit (Section 65): Conducted by GST officers at the taxpayer's business premises or at the department's office — examining records, accounts, returns, and related documents.
• Audit by CA/CMA (GSTR-9C — now a Self-Certified Reconciliation): Until FY 2020-21, taxpayers with turnover above ₹2 crore were required to get their accounts audited by a CA/CMA and file GSTR-9C (reconciliation statement). From FY 2021-22, GSTR-9C has been converted into a self-certified statement — but the reconciliation discipline it imposes remains equally important.

2. Departmental GST Audit (Section 65)

The GST Commissioner can authorise a GST audit of any registered taxpayer. Prior notice of at least 15 working days is given to the taxpayer. The audit is conducted at the taxpayer's principal place of business or registered office. Key aspects examined:

• Whether turnover declared in GST returns matches books of accounts and financial statements
• Correctness of tax rate applied on each category of supply
• Eligibility and accuracy of ITC claimed — blocked credits, proportionate reversal, reversal on exempt supplies
• Correctness of reverse charge mechanism (RCM) payments
• E-invoicing compliance (for eligible taxpayers)
• E-way bill compliance for movement of goods
• Place of supply determination — especially for inter-state services and exports
• Valuation of supply — ensuring related-party transactions are at arm's length

After the audit, the officer issues a report within 30 days — and if discrepancies are found, a show cause notice for demand and penalty follows.

3. GSTR-9C — Annual GST Reconciliation Statement

GSTR-9C is the annual reconciliation statement filed along with GSTR-9 (Annual GST Return) for taxpayers with turnover above ₹5 crore (current threshold). It reconciles:

• Turnover: Turnover as per audited financial statements vs. turnover declared in GST returns (GSTR-1) — explaining differences like advance receipts, credit notes, exempted supplies, etc.
• Tax Paid: Tax paid as per financial statements vs. tax paid as per GSTR-3B — explaining any differences due to RCM, timing differences, or corrections.
• ITC: ITC booked in books of accounts vs. ITC claimed in GSTR-3B vs. ITC available in GSTR-2B.

GSTR-9C is a self-certification from FY 2021-22 onwards — meaning the taxpayer (typically with CA assistance) certifies the reconciliation rather than having a CA issue an audit opinion. However, the underlying reconciliation work is just as rigorous as before.

4. Internal GST Audit — Proactive CA-Led Review

Beyond the statutory requirements, leading CA firms recommend an internal GST audit every 6–12 months — a proactive, self-initiated review of GST compliance covering:

• GSTR-1 vs GSTR-3B reconciliation — ensuring what was declared as outward supplies was actually paid
• GSTR-2B vs ITC in books — identifying unclaimed ITC and ineligible ITC claimed
• Section 17(5) blocked credit review — ensuring ITC on non-eligible items (motor vehicles, food, personal expenses) was not claimed
• ITC reversal review — whether ITC has been proportionately reversed on exempt and non-business supplies
• Reverse Charge Mechanism compliance — whether RCM was paid and ITC correctly claimed where eligible
• E-invoicing compliance for eligible taxpayers
• HSN/SAC code accuracy on invoices
• Annual return (GSTR-9) preparation review

5. Common GST Issues Found in Audits

• ITC claimed on invoices not reflected in GSTR-2B (supplier hasn't filed GSTR-1)
• ITC on blocked credits (Section 17(5)) — motor vehicles, works contract for own use, food & beverages
• Mismatch between turnover in GSTR-1 and GSTR-3B due to timing differences not reconciled
• Incorrect classification of supply as exempt or nil-rated without valid basis
• Non-payment of RCM on import of services, GTA (Goods Transport Agency), security services, etc.
• E-way bill violations — goods moved without e-way bill or with expired e-way bill
• Non-reversal of ITC on credit notes received from suppliers
• Wrong place of supply leading to wrong IGST/CGST/SGST application