You don't pay it back because this is a new, one-year credit that augments your refund. You will reconcile it on your return next year, but it has no impact on your bottom line and will not reduce your refund. In essence, it reduces your tax liability by the amount of the rebate. If you, for some reason, receive more for the rebate than you qualify for when you reconcile next year, it zeroes out. You don't pay it back and it doesn't reduce your refund.
2/10/08 at 12:25pm