Section 44AB (need to read 44AD, 44ADA, 44AE, 44BB & 44BBB too) gives the provisions relating to the class of taxpayers who are required to get their accounts audited from a chartered accountant. The audit under section 44AB aims to ascertain the compliance of various provisions of the Income-tax Law and the fulfillment of other requirements of the Income-tax Law. The audit conducted by the chartered accountant of the accounts of the taxpayer in pursuance of the requirement of section 44AB​ is called tax audit.
The chartered accountant conducting the tax audit is required to give his findings, observation, etc., in the form of audit report. The report of tax audit is to be given by the chartered accountant in Form Nos. 3CA/3CB and ​3CD. ​
A proper audit for tax purposes would ensure that the books of account and other records are properly maintained, that they truly reflect the income of the taxpayer and claims for deduction are correctly made by him. Such audit would also help in checking fraudulent practices. It can also facilitate the administration of tax laws by a proper presentation of accounts before the tax authorities and considerably save the time of Assessing Officers in carrying out routine verifications, like checking correctness of totals and verifying whether purchases and sales are properly vouched for or not.
According to section 271B, if any person who is required to comply with section 44AB fails to get his accounts audited in respect of any year or years as required under section 44AB or furnish such report as required under section 44AB, the Assessing Officer may impose a penalty. The penalty shall be lower of the following amounts:
(a) 0.5% of the total sales, turnover or gross receipts, as the case may be, in business, or of the gross receipts in profession, in such year or years.
(b) Rs. 1,50,000.”