I was reading comments on this post, but the situation we have is slightly different so I couldn’t find the right answer. My husband lived with his ex in 2018 and they separated in December that year. They have two kids together and they were never married. After separation prior to any court order his ex filed taxes for 2018 and claimed both of the kids. My husband thought that he couldn’t do anything about it so he just filed taxes without claiming dependents. According to federal tax laws, they lived together with the kids and he had higher AGI so he would have the right to claim the kids. Could he amend his return for that year now or is that something that should be taken to court?
