I recently obtained joint custody with my ex in-laws(the grandparents). I have primary custody and I pay child support, they have secondary custody. My kids stay with my ex in-laws thru the week during the school year because my work requires me to travel. I have them every weekend, all holidays, and half the time thru the summer. My question is: Who has the right to claim the children on there taxes? Me or them? Since I'm the parent and pay child support shouldn't I have all rights to claim them? I know the laws can be strange sometimes.