As per section 68(1) of the Finance Act, 1994, every person providing taxable services to any other person shall pay service tax at the rate specified in section 66. Normally, the liability to pay service tax lies with the service provider. He shall collect the service tax from the service recipients and thus pay it to the authorities.
Reverse charge mechanism was introduced in service tax with effect from 1/7/2012. With this, service receiver is also liable to file return and pay service tax in respect of service tax they have to collect and pay to the authority.