Circular No : 497 -Income Tax The provision of section 203A introduced through the Finance Act, 1987, with effect from 1-6-1987, makes it obligatory for all persons responsible for deducting tax at source to apply for allotment of Tax-deduction Account Number (TAN) and, after obtaining it, quote the same in the challans, TDS certificates, periodical returns, etc. The form of application for allotment of TAN [Form No. 49B
