If you have custody more than half the year, but it is the other parent’s turn to claim the children under a divorce decree, you are required to give the parent a signed form 8332. Then, the other parent is required to submit that form to the IRS. If the other parent has a signed form 8332 and enters it in their tax program, then they will get the child tax credit but will not claim other improper benefits and there won’t be a conflict with the e-file. So possibly you gave this form to the other parent and they ignored it, or possibly you have not given them the proper form. You should do this now (if you did not already) to protect yourself when the IRS investigates. The custodial parent must give the noncustodial parent a form 8332 for each year that the noncustodial parent is allowed to claim the children as dependents.
you should also gather proof that the children lived with you more than half the year, so that you can send copies to the IRS when they investigate. The IRS is most easily convinced by information from third parties. Things such as letters from your children’s school or doctors or school bus schedules, or other documents sent by third parties to your address on behalf of the children. Social media posts showing you and the children doing activities will also help.
