Audit powers under CGST Act: formal notice, verification of records, audit findings communicated and recovery avenues available. Statutory audit procedure under Section 65 and Rule 101 empowers the Commissioner or authorised officers to audit a financial year (or part) at business premises or auditor's office, requires at least fifteen working days' notice in Form GST ADT-01, mandates completion normally within three months (with permitted extensions), obliges verification of books, returns, input tax credit, exemptions and refunds, requires recording of observations, affords the taxpayer a chance to reply, and culminates in a Final Audit Report communicated in FORM GST ADT-02 with reasons and rights and obligations.