Look I'm posting for my brother-in-law, and he is court ordered by the state of Tennessee (even though he is a resident, now of North Carolina) to pay his ex-wife child support. He makes less money now than he was and they court ordered the child support be reduced effective November 1, 2001, but they didn't get the court order until the end of December, 2001 and they had already paid her the prior amount for November and December, 2001. Basically my question is can he legally deduct the extra amount from his January, 2002 payment (the amount he unknowingly overpaid for November and December)? Thanks and I would appreciate any help ASAP! Thanks.