<prompt> Human: My niece lives with her mother and all of her expenses are covered by the mother. This tax year, the Father proceeded to claim her on his tax return. So my sister-in-laws tax return was rejected because she also tried to claim her daughter, and rightly so. The only legal paperwork she has claims that the Father can claim her on alternating years if he is up to date with his child support payments. He is up to date with his payments, but still has a huge lump some that he owes. Regardless of this, how is it legal for him to claim her if the daughter lives with the mother and all expenses are covered by the mother?  <response>: If father and mother are divorced, separated, or not living together, the noncustodial parent which is the father, since you say niece lived with mother all year can only claim the exemption if the mother signs a Form 8332 releasing her claim to the exemption if the divorce was after 2008. If earlier divorce date, the wording in the decree needs to meet certain rules specified below, which includes having a statement that the noncustodial parent can claim the child without regard to any condition such as payment of support. It doesnt sound like that is the case with their legal paperwork.If this didnt happen, then mother should file and claim the girl if the girl is a qualifying child. Then the IRS will send notices to both and ask the person in error to amend their return.Because mother cannot e-file now, mother will need to file on paper. It doesnt mean she cant claim the child. 