I have to assume you're the legal parents. If your boyfriend is not a legal parent, then you'd have to get a waiver from the legal parent for him to claim them, which is a hassle. So if he is the legal parent and you both provided income to the home and provided for the children, then yes, you could split them up. Each of you could claim one child as a dependent (again, I'm assuming you have two children, you can't both claim the same child). However, check to see if one of you is in a higher tax bracket than the other (you can google 2015 single filer tax brackets to get the number). If one of you has income in a higher bracket than the other, then that person should claim BOTH children because that person is paying the most taxes, make sense? If you're both in the SAME tax bracket, then I would still put them with the highest income earner. If you're both in the 10% bracket, then it doesn't matter who claims who, the deduction will be exactly the same.
