TAN or Tax Deduction and Collection Number (TAN) is an alphanumeric 10 digit number required by a person who is liable to deduct TDS and file TDS return. Thus such person must make an application within a month in which TDS was deducted for allotment of Tax Deduction and Collection Number (TAN) in form 49B. This number allotted is mandatory to mention in all TDS Certificates issued, returns, challans etc. Tax is deducted by the payer and is remitted to the government by the payer, on behalf of payee. Legal Suvidha Providers can help easily filing your TDS Return.