As per the Income Tax Act, 1961 tax must be deducted or collected at the time of payment. In such cases, the tax deductors are required to deduct file TDS / TCS return while and pay the TDS collected. TAN is used as identification while filing TDS returns. Failure to apply for TAN or not quoting the same in the specified documents attracts a penalty of Rs. 10,000.
If you forgot your TAN Number, then you can use know your TAN tool by entering Tax deductor details.