Rate of tax shall be of the date of receipt of payment if the assessee has chosen to pay tax on the advance amount received

Explanation in Rule 6(1) does not make any provision as to which rate of tax will apply in situation like the one at hand (whether that on date of receipt of value or that on date of providing service). This explanation says that the service provider need to pay tax only on that portion of value for which service tax has been provided. In the instant case the Appellant paid tax on the full value received. The department did not take any objection to such payment in advance. So at a later date when the rate went up, there is no reason for the department to turn around and say that the Appellant...