A divorced couple have an agreement that the ex-husband will pass 50% (after tax) of any commission through to his ex-wife. He made an error on his tax withholding and owed $60,000 to the IRS for tax underpayment. He paid the IRS and is asking that his ex-wife repay him the $30,000 (half of what he owed the IRS). This situation presents several questions. Is the ex-wife obligated to pay the ex-husband the $30,000 for his taxes owed? If she does pay him can she deduct this as taxes paid when she prepares her 2013 return? Because he withheld too little in taxes and therefore passed more than he should have to his ex-wife, should she repay the amount of overpayment instead of paying the $30,000 in taxes? Is she required to repay this amount to her ex-husband? Also, will the ex-wife have to report the commissions as taxable income on her 2013 return? There is a separate payment for spousal support. Thanks for your help!