I accidentally claimed the additional earned income tax for 2 of my children instead of 1 but I didnt claim two children this year. The other parent is claiming one of the children. What now?

Please be aware if the child lived with you for more than half the year (you are the custodial parent) and you release the dependent to be claimed by the other because of an agreement then the Earned Income Credit (EIC) and Child and Dependent Credit can only be claimed by you as the custodial parent. The other parent can only receive the Child Tax Credit. Please see IRS EIC Divorced and Separated Parents for additional information.

If the child didn't live with you but you claimed your child then you will have to file an amended return should your return get accepted.  Please see FAQ How to amend a tax return for instructions.

If both parents claimed the same child on their return then one of your returns will get rejected. If your return gets rejected and you didn't have the right to claim EIC then all you have to do is make the correction.