Deductions & credits

The IRS told him no such thing, or if they did he misstated the situation.

If this is a recent divorcee decree, the IRS does not care one wit about it.  They only care about where the child lived and the 8332 form.   If you do not give him a 8332 then he cannot (legally) claim the child reguardless of what the decree says.   Like I said the IRS does not referee divorce decree enforcement, he would have to pursue local legal action if he thinks you are violating the decree.  A local judge can enforce it, not the IRS.   

Living with the child is not a requirement to be able to claim the exemption and child tax credit, but he does need the 8332 form signed by you.  Like I said, if the decree does give him the right to claim, perhaps you should consult your attorney before you violate the decree and refuse to issue him that form.

You can still claim the EIC and child care credit and file Head of Household it that applies.

He can, of course  claim the child anyway without the 8332 form.   You can just file claiming the child that you are entitled to (if he e-files first, your return  will reject and you will have to paper file).

The IRS will pay both refunds, but within a year or so (the IRS is slow) you will both get letters asking if you claimed the child in error and to amend your return to remove the child if you did.   Do not ignore the letter, respond that you are the custodial parent and did not release the exemption.

The IRS will send a 2nd letter asking for evidence that the child lived with you,  school records, doctor records, and other records can establish that.

The IRS will make a determination as to who is entitled to claim, which should be you.  The other parent will have to pay back any refund plus interest and possible penalties.
**Disclaimer: This post is for discussion purposes only and is NOT tax advice. The author takes no responsibility for the accuracy of any information in this post.**