TAN or Tax Deduction and Collection Account Number is a 10 digit alpha numeric number required to be obtained by all persons who are responsible for deducting or collecting tax. Under Section 203A of the Income Tax Act, 1961, it is mandatory to quote Tax Deduction Account Number (TAN) allotted by the Income Tax Department (ITD) on all TDS returns. Since last few years ITD has revised the structure of TAN. It is a unique 10 digit alphanumeric code. Accordingly, they have issued TAN in this new format to all existing TAN holders.