I recently efiled taxes for my husband and myself only to have them rejected because someone already claimed my son. It turns out that my exhusband claimed him after we discussed it and I told him no. I have custody of my son, a divorce decree stating that I claim him and I did not sign a release form.

What should I do now? I feel I should report him, but don't know how. I know I must now file by mail, but am worried about how long this will hold up my return. My exhusband filed at one of those places that give you the return check right away. Any help would be greatly appreciated.

I would Report him to family court and the IRS

How Do You Report Suspected Tax Fraud Activity? (http://www.irs.gov/compliance/enforcement/article/0,,id=106778,00.html)

Yes, report him to the IRS.

On your tax return, put on a cover letter explaining the situation. Add the copy of the divorce decree with the pertinent section highlighted. Since it is obvious that you are the custodial parent with the right to claim your son, the IRS WILL give you the exemption, then go after your ex-husband for the money he got, plus interest, plus AT least a 25% penalty, and possibly a 100% fraudulent filing penalty.

Of course, you COULD call your ex-husband, tell him what you ae going to do, and give him the chance to amend his return and "unclaim" his son. It would save him some money for sure.

But your case is a SLAM DUNK in your favor. It may take about 4 to 8 weeks, but you WILL get the exemption in the end.