18 February 2011
Pl see http://taxguru.in/income-tax/minimum-alternate-tax-mat-provisions-under-the-income-tax-act-for-a-y-2010-11-and-a-y-2011-12.html
15 March 2011
Step 1: Compute tax under normal provisions
Step 2: Compute tax @ MAT rate - on the book profits i.e profits as per audited accounts +_ certain adjustments laid down in Section 115 - and the rate is 18% which has been increased to 18.5% in the budget.
2) If tax under Step 2 is higher - then MAT is applicable i.e you have to pay tht tax even if your tax as per normal computation is Nil.