Tax deducted at source or TDS is mandatory to be filed by a Business entity, which is making any kind of payment to employees or vendors beyond certain limits. The Income Tax Act states that tax will be deducted at source at different rates as provided. TDS return is to be submitted to the Income Tax Department online and it is a quarterly statement, while tax deducted should be paid monthly. To start deducting and paying taxes first part is to obtain TAN number, After that on each payment made, you need to deduct certain percent of payment as TDS and pay that amount to Govt. online challans and file TDS return every quarter. Failure to do so you can face disallowance of expenses, which in fact will increase your tax outlay. Apart from that if you have taken a TAN number and deducted taxes but not paid it to Govt and TDS return has not been filed, you will be liable for Late filing fee which is Rs 300 per day along with penalty and prosecution.