Tax audit ensures mandatory chartered accountant examination of accounts and reporting in prescribed audit forms for tax compliance. A tax audit is the statutory examination of a taxpayer's business or professional accounts by a chartered accountant to verify compliance with income tax provisions. Section 44AB prescribes which taxpayers must obtain the audit. The auditor must record findings and furnish an audit report in the prescribed formats, specifically Form Nos. 3CA/3CB and 3CD, to document the audit observations and required particulars for tax compliance.