GST Audit: Section 65 vs Section 66 — Response Strategy
Quick Answer
GST audit is conducted under two distinct provisions of the CGST Act: Section 65 (audit by tax authorities — conducted by the department’s own officers, completed within 3 months extendable by 6 months) and Section 66 (special audit — conducted by an external CA or CMA nominated by the Commissioner, report within 90 days extendable by 90 days). Rule 101 of the CGST Rules prescribes the procedure. Audit findings can lead to demand notices under Section 73 or Section 74. At Virtual Auditor, we represent taxpayers during GST audits — from initial response to the ADT-01 notice through post-audit demand proceedings and appeals. Our approach: prepare proactively, respond precisely, and concede nothing without clear legal basis.
Definition — Audit by Tax Authorities (Section 65): A process whereby the Commissioner or any officer authorised by him undertakes an audit of any registered person for a specified period, at the registered person’s place of business or in the office of the tax authority. The audit examines the correctness of turnover declared, taxes paid, refunds claimed, input tax credit availed, and assesses compliance with the provisions of the CGST Act and rules. The audit is initiated by a notice in Form GST ADT-01 at least 15 working days before the commencement of the audit.
Definition — Special Audit (Section 66): An audit ordered by the Commissioner during any stage of scrutiny, inquiry, investigation, or any other proceedings, when the Commissioner is of the opinion that the value has not been correctly declared or the credit availed is not within the normal limits. The audit is conducted by a Chartered Accountant or Cost Accountant nominated by the Commissioner, at the expense of the Commissioner (not the taxpayer). The nominated auditor submits a report in Form GST ADT-04.
Section 65 vs Section 66: Comparative Analysis
| Parameter | Section 65 — Audit by Tax Authorities | Section 66 — Special Audit |
|---|---|---|
| Who conducts | Department officers authorised by the Commissioner | External CA or CMA nominated by the Commissioner |
| Trigger | Risk-based selection, routine audit programme, or specific intelligence | During scrutiny/inquiry/investigation when the case is complex or values appear incorrect |
| Prior approval | Commissioner or authorised officer | Commissioner (with prior intimation to the taxpayer) |
| Notice | Form GST ADT-01 — at least 15 working days before commencement | Direction to the taxpayer specifying the nominated auditor and period |
| Time limit | 3 months from commencement, extendable by 6 months (Commissioner’s order) | 90 days from commencement, extendable by 90 days (Commissioner’s order) |
| Audit report | Form GST ADT-02 — communicated to the taxpayer within 30 days of completion | Form GST ADT-04 — submitted by the nominated CA/CMA |
| Cost | Borne by the department | Borne by the Commissioner (not the taxpayer) |
| Outcome | If discrepancies found: proceedings under Section 73 or 74 | If discrepancies found: proceedings under Section 73 or 74 |
| Taxpayer’s obligation | Provide access to records, afford facility for verification, furnish information | Provide access to records and provide necessary assistance to the nominated auditor |
Common Triggers for GST Audit Selection
The GSTN risk management system and departmental intelligence units use data analytics to identify taxpayers for audit. Based on our experience at Virtual Auditor, the most common triggers are:
Data-Driven Triggers
- GSTR-1 vs GSTR-3B mismatch: Turnover declared in GSTR-1 (invoice-wise) exceeds or falls short of the turnover declared in GSTR-3B (summary). This is the single most common trigger
- ITC mismatch: ITC claimed in GSTR-3B exceeds the ITC reflected in GSTR-2B by a material percentage. The department considers anything above 5-10% variance as a flag
- High refund claims: Frequent or large IGST refund claims on exports, particularly where the input-to-output ratio appears abnormal
- Abnormal ITC ratio: ITC as a percentage of output tax that deviates significantly from the industry average for the HSN codes reported
- E-way bill anomalies: High value of e-way bills generated without corresponding GSTR-1 invoices, or vice versa
- Turnover drop: Significant decline in declared turnover compared to previous years without any apparent commercial reason
Intelligence-Based Triggers
- Supplier flagged as a fake invoice operator — all buyers of that supplier are audited for ITC verification
- Information from other agencies (Income Tax, Customs, Enforcement Directorate)
- Third-party information — complaints from competitors, customers, or former employees
- Discrepancies found during the audit of a related entity (group company, associate, or joint venture partner)
Section 65 Audit: Step-by-Step Procedure
Step 1: Receipt of ADT-01 Notice
The audit commences with the issuance of Form GST ADT-01, served at least 15 working days before the date of commencement of the audit. The notice specifies: the period of audit, the place of audit (registered person’s premises or the department’s office), and the name of the authorised officer conducting the audit.
On receiving ADT-01, the taxpayer should immediately:
- Verify the authority of the issuing officer — is the officer authorised by the Commissioner?
- Note the audit period — ensure it does not overlap with a period already audited
- Begin assembling the required records and documents
- Engage a qualified professional (CA or tax consultant) to coordinate the audit response
Step 2: Document Preparation
The following documents must be organised and ready before the audit commences:
| Category | Documents |
|---|---|
| Returns | All GSTR-1, GSTR-3B, GSTR-9, GSTR-9C filed for the audit period |
| Books of Account | Trial balance, general ledger, P&L account, balance sheet for the audit period |
| Purchase Records | Purchase register, supplier invoices, GSTR-2B downloads, ITC register |
| Sales Records | Sales register, tax invoices (sample set), credit notes, debit notes |
| Bank Records | Bank statements for all business accounts covering the audit period |
| Stock Records | Stock register, inventory valuation, stock audit reports (if conducted) |
| E-way Bills | E-way bill generation records, cancellation records, Part B updates |
| Contracts | Key contracts with suppliers, customers, service providers |
| Export Documents | Shipping bills, BRC/FIRC, LUT copies, refund applications |
| RCM Records | Reverse charge payment details, self-invoices issued, ITC claimed on RCM |
Step 3: Audit Conduct — Cooperation and Strategy
During the audit, the registered person is obligated under Section 65(4) to provide the officer access to all records, afford facility for verification, and furnish such information as the officer may require. Non-cooperation can result in adverse inferences and penalty under Section 122(3)(c).
However, cooperation does not mean concession. The strategic approach we follow at Virtual Auditor:
- Provide what is asked, not what is assumed: Respond to specific audit queries with specific documents. Do not volunteer additional information that has not been requested
- Document everything: Maintain a log of all documents submitted, queries raised, and responses provided. Insist on written acknowledgement of documents submitted
- Address queries in writing: Where the auditor raises oral queries, request that they be put in writing. Respond in writing with supporting documentation. This creates an audit trail that protects the taxpayer in subsequent proceedings
- Do not accept audit observations on the spot: If the auditor raises an observation regarding short payment or excess ITC, request time to examine the issue and respond with a detailed reply. Do not make voluntary payments during the audit without proper analysis
- Identify the legal basis for each observation: Every audit observation must be grounded in a specific provision of the CGST Act or Rules. If the auditor’s observation is based on an interpretation of law that is debatable, note it as a point of disagreement
Step 4: Audit Findings — Form GST ADT-02
On conclusion of the audit, the proper officer informs the registered person of the audit findings, the reasons for the findings, and the registered person’s rights and obligations. The findings are communicated in Form GST ADT-02 within 30 days of the completion of the audit. The ADT-02 specifies:
- The discrepancies found during the audit
- The amount of tax short-paid, excess ITC availed, or incorrect refund claimed
- The provisions of law under which the discrepancy falls
- The action proposed (demand under Section 73 or 74)
Step 5: Post-Audit Response
After receiving ADT-02, the taxpayer has three options:
- Accept and pay: If the audit findings are correct, pay the tax, interest, and applicable penalty through DRC-03. Under Section 73(5), if payment is made before the issuance of SCN, the penalty is nil (for non-fraud cases). Under Section 74(5), the penalty is reduced to 15%
- Partially accept: Pay the undisputed portion through DRC-03 and contest the disputed portion. This demonstrates bona fide conduct and may reduce penalty exposure
- Fully contest: If the audit observations are incorrect or based on debatable legal positions, do not pay and prepare for the demand proceedings that will follow. The department will issue a show cause notice (DRC-01) under Section 73 or 74, and the taxpayer can file a detailed reply
Section 66 Special Audit: Procedure and Response
When Is Section 66 Invoked?
Section 66 is invoked when the Commissioner, during any stage of scrutiny, inquiry, investigation, or any other proceeding, forms the opinion that:
- The value of supply has not been correctly declared, OR
- The credit availed is not within the normal limits
The Commissioner must have regard to the nature of the business and the complexity of the case. In practice, Section 66 is invoked in cases involving: complex inter-company transactions, transfer pricing issues in GST, multi-layered supply chains where value addition at each stage needs verification, cases involving related party transactions under Rule 28, and cases where the taxpayer’s records are maintained in a specialised accounting system requiring expert examination.
Taxpayer’s Rights During Special Audit
- Right to be heard: Before directing a special audit, the Commissioner must give the taxpayer an opportunity of being heard — Section 66(1). This is a pre-condition, and failure to grant this opportunity renders the special audit direction liable to be quashed
- Cost not borne by taxpayer: The expenses of the special audit, including the auditor’s fees, are determined and paid by the Commissioner — Section 66(4). The taxpayer is not liable for any audit cost
- Right to receive audit report: The audit report in Form GST ADT-04 must be submitted to the Commissioner within 90 days (extendable by 90 days). A copy of the report must be provided to the taxpayer
- Right to respond: The taxpayer can submit a response to the audit report before any demand proceedings are initiated
Challenging a Section 66 Direction
A Section 66 direction can be challenged on the following grounds:
- The Commissioner did not grant an opportunity of being heard before directing the special audit
- The opinion regarding incorrect valuation or abnormal ITC is not supported by material on record
- The direction is vague — it does not specify the period, the issues to be examined, or the reasons for invoking Section 66 instead of Section 65
- The special audit has been directed after the time limit for issuing a demand notice under Section 73/74 has expired — in such cases, the special audit serves no purpose and is an exercise of power without jurisdiction
The challenge is typically made through a writ petition before the jurisdictional High Court, as there is no specific appellate remedy against a Section 66 direction within the CGST Act.
Expert Insight — CA V. Viswanathan, IBBI/RV/03/2019/12333
The critical moment in any GST audit is the first 48 hours after receiving the ADT-01 notice. In our practice at Virtual Auditor, we conduct a pre-audit health check for every client: reconcile GSTR-1 vs GSTR-3B for the entire audit period, verify ITC claims against GSTR-2B, validate HSN-wise classification, and identify any voluntary corrections that can be made via DRC-03 before the audit commences. This pre-audit correction significantly reduces the audit exposure — paying voluntarily before the audit starts attracts nil penalty under Section 73(5) for non-fraud cases, whereas the same payment after an audit finding carries at least 10% penalty. For Section 66 special audits, we actively participate in the hearing process and ensure the taxpayer’s interests are represented to the nominated CA/CMA throughout the audit. If the audit results in a demand, see our guides on Section 107 appeal and GST demand orders.
Post-Audit Demand Proceedings: Section 73 vs Section 74
If the audit findings result in a demand, the proper officer initiates proceedings under Section 73 (non-fraud) or Section 74 (fraud, suppression, wilful misstatement). The choice between Section 73 and 74 depends on whether the discrepancy is attributable to genuine error or intentional evasion.
| Parameter | Section 73 | Section 74 |
|---|---|---|
| Grounds | Non-fraud: error, omission, wrong interpretation | Fraud, wilful misstatement, suppression of facts |
| Time limit for SCN | 2 years 9 months from annual return due date | 4 years 6 months from annual return due date |
| Time limit for order | 3 years from annual return due date | 5 years from annual return due date |
| Penalty | 10% of tax or ₹10,000 (higher) | 100% of tax |
| Voluntary payment (pre-SCN) | Tax + interest; NIL penalty | Tax + interest + 15% penalty |
The key defence in post-audit proceedings is to demonstrate that the discrepancy, if any, is attributable to a bona fide error — not fraud or suppression. If the taxpayer has filed all returns, disclosed all transactions, and maintained proper books of account, the charge of suppression is difficult to sustain. This re-classification from Section 74 to Section 73 reduces the penalty from 100% to 10%.
Rule 101: Examination of Returns — Scrutiny
Rule 101 of the CGST Rules provides the procedure for scrutiny of returns by the proper officer. Scrutiny is distinct from audit — it is a desk-based examination of the return data without visiting the taxpayer’s premises. If the officer finds any discrepancy during scrutiny, a notice in Form ASMT-10 is issued to the taxpayer, requiring an explanation within 30 days via Form ASMT-11.
If the explanation is satisfactory, the officer drops the proceedings via Form ASMT-12. If the explanation is not satisfactory, the officer may initiate audit under Section 65, special audit under Section 66, or demand proceedings under Section 73/74 directly.
Scrutiny under Rule 101 is increasingly being used as a precursor to audit. A well-drafted ASMT-11 response can prevent the escalation to a full audit.
Fees for GST Audit Representation
| Service | Fee (Excl. GST) |
|---|---|
| Pre-audit health check and reconciliation | From ₹25,000 |
| Section 65 audit representation (complete) | From ₹50,000 |
| Section 66 special audit coordination | From ₹75,000 |
| Post-audit DRC-01 reply and adjudication | From ₹40,000 |
| Section 107 appeal (post-audit demand) | From ₹40,000 |
| ASMT-10 scrutiny notice reply | From ₹15,000 |
For detailed pricing, visit virtualauditor.in/pricing.
Summary
GST audit operates under two provisions: Section 65 (audit by department officers, 3 months + 6 months extension, findings in ADT-02) and Section 66 (special audit by nominated CA/CMA, 90 + 90 days, report in ADT-04, cost borne by Commissioner). Rule 101 governs pre-audit scrutiny via ASMT-10. Common triggers include GSTR-1/3B turnover mismatches, excess ITC claims, high refund volumes, and GSTN risk profiling. The response strategy centres on: proactive pre-audit correction (nil penalty under Section 73(5)), precise document organisation, written responses to all queries, and refusal to make voluntary payments without proper analysis. Audit findings can lead to demand proceedings under Section 73 (10% penalty) or Section 74 (100% penalty) — re-classifying from 74 to 73 is a key defence objective. Virtual Auditor provides end-to-end audit representation from pre-audit health check through post-audit demand proceedings and appeals.
Frequently Asked Questions
What is a GST audit under Section 65?
Section 65 empowers the Commissioner or authorised officer to audit any registered person for a specified period. The audit examines the correctness of turnover, taxes paid, refunds claimed, and ITC availed. It must be completed within 3 months from commencement, extendable by 6 months. Notice is issued in Form ADT-01 at least 15 working days before commencement.
What is a special audit under Section 66?
Section 66 provides for a special audit by a CA or CMA nominated by the Commissioner, triggered during scrutiny, inquiry, or investigation when the Commissioner believes values have not been correctly declared or ITC is abnormal. The report (ADT-04) is due within 90 days (extendable by 90 days). The audit cost is borne by the Commissioner.
What is the difference between Section 65 and Section 66 audit?
Section 65 is conducted by department officers as a routine or risk-based audit. Section 66 is conducted by an external CA/CMA for complex cases. Section 65 has a 3+6 month timeline; Section 66 has a 90+90 day timeline. Section 66 requires the Commissioner to grant the taxpayer an opportunity of being heard before directing the audit.
What documents should be kept ready for a GST audit?
GST returns (GSTR-1, 3B, 9, 9C), purchase and sales registers, ITC register with GSTR-2B reconciliation, bank statements, stock records, e-way bills, export documentation, contracts, accounting data (trial balance, ledger, P&L, balance sheet), credit/debit note register, and reverse charge payment details.
Can the audit result in a demand notice?
Yes. Discrepancies found during audit can lead to demand under Section 73 (non-fraud, 10% penalty) or Section 74 (fraud/suppression, 100% penalty). Findings are communicated in ADT-02. If unresolved, a DRC-01 show cause notice follows. The taxpayer can contest through reply and Section 107 appeal.
What are the common triggers for a GST audit?
GSTR-1 vs GSTR-3B turnover mismatch, ITC claimed exceeding GSTR-2B, high refund claims, abnormal ITC-to-output ratio, frequent return amendments, non-filing or delayed filing, GSTN risk profiling flags, and intelligence from other agencies. Contact Virtual Auditor for pre-audit preparation.
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