which is corret?

[dustp777]

The state pays 50% of the amount that it is billed in the quarter immediately following billing and 50% two quarters after receiving a bill.

The state pays 50% of the amount for which it is billed in the quarter immediately following billing and 50% two quarters after receiving a bill.



In the above sentences, which is correct? and the reason?

Please inform me in detail..

Thanks in advance~

[Soup]

Either variant is possible.