Minimum Alternate Tax curbs zero-tax corporate profits by imposing a minimum tax liability despite book-to-tax differences. Minimum Alternate Tax (MAT) obliges corporate taxpayers who report substantial book profits yet claim negligible taxable income to pay a statutory minimum tax, addressing variances arising from differing allowances and depreciation methods between company law and income-tax computation; it functions as a floor on tax liability to bring zero-tax companies into the tax net and strengthen corporate tax compliance.