Excess service tax paid

Dear all,

I have paid servcie tax challan in advance for the services provided. The bill to Client will be raised in the second half i.e; in October. My query is as I have paid the challans in advance, the same will be carried forward for setoff while filing my service tax return for April - September. But I'm confused as to how to show this amount in my April-September service tax return so that I will be allowed to setoff this amount in my October - March service tax return.

Thanks in advance.