@Hooked38
For alimony, you can claim it on your tax return regardless of her cooperation, and you will show your divorce instrument to the IRS when they ask questions.
For the child tax credit, you are correct that the IRS will not award the dependent to you on the basis of the divorce decree, and you must have a form 8332. If your ex won’t provide it, you have to go back to Family Court.
If I might make a suggestion, completely outside my training or professional expertise, I think it’s time for some unconventional thinking. I would think about proposing to your ex and to the judge that your base alimony amount be reduced by 30% and make it non-taxable/non-deductible (since the modification would take affect after 2019). The reduced amount would compensate for the tax effects. That way, your tax return is not entangled with your ex anymore. In other words, cut the alimony amount and forget about the tax deduction. I would also think about further modifying the alimony or child support award to reduce the annual amount rather than trading dependents. Under current tax law, the child tax credit is $3000, but it reduces back to $2000 for 2022 and afterwards unless Congress passes a new increase. So the effect of claiming a child as a dependent will save most taxpayers about $2000 a year. If you had for example, two children, you could simply modify the order to reduce your alimony or child support by $4000 every other year or by $2000 every year and then not try to claim the children as a dependent. That way you get the same financial benefit but you are not subject to your ex‘s cooperation.
Changing tax laws should probably require changing approaches to divorce finances and custody issues. But this is just my uninformed opinion. Good luck.
