Minimum Alternate Tax requirement ensures companies pay tax based on book profit when taxable income is lower than book profit tax. Where a company's tax under the Act is less than the tax computed by reference to its book profit, the book profit is deemed to be the company's total income and tax is charged at the rate specified; book profit is computed from the statement of profit and loss prepared under the applicable companies law and accounting standards with prescribed add backs and deductions, IAS/Ind AS transition and demerger rules, and is certified by an accountant in the prescribed form.