Unfortunately, any tax return filed by the children's father, claiming them as dependents, while their Social Security Numbers are in the IRS system as "claimed" on another tax return, will be flagged for review and not processed until the matter is resolved. It would be in his best interest to wait, within the filing deadline of April 15, until your amended return has been accepted by the IRS, processed, and any refund or tax due on your return has been issued or paid.

Amended returns cannot be e-filed. Your must print, sign, and mail Form 1040X, along with a corrected copy of any affected form or schedule.

The IRS frequently takes as much as ten weeks to fully process amended returns.