No.
The custodial parent has
first priority on claiming the children on her taxes; regardless of the amount
of support provided by the non-custodial parent. The IRS goes by physical custody, not legal custody. The non-custodial parent can
only claim the child as a dependent if the custodial parent gives permission
(on form 8332) or if it's spelled out in a pre 2009 divorce decree.Even if a divorce decree, dated after 2008, gives the non-custodial parent the
right to claim the child, he must still get form 8332 from the custodial
parent. A properly worded decree should require her to provide that form. https://www.irs.gov/pub/irs-pdf/f8332.pdf
If someone else claimed your
child inappropriately, and if they file first, your return will be rejected if
e-filed. You would then need to file a return on paper, claiming the
child as appropriate. The IRS will process your return and send you
your refund, in the normal time. Shortly (up to a year)
thereafter, you'll receive a letter from the IRS, stating that your
child was claimed on another return. It will tell you that if you made a
mistake to file an amended return and if you didn't make a mistake to do
nothing. The other party will get the same letter you did. If one of you
doesn't file an amended return, unclaiming the child, the next letter, from the
IRS, will require you to provide proof. Be sure to reply in a timely manner.
Winner gets the tax benefits;
loser gets to pay the IRS back with penalties and interest. The
custodial parent almost always wins. The non-custodial parent can only
claim the child as a dependent if the custodial parent gives permission (on
form 8332) or if it's spelled out in a pre 2009 divorce decree.
https://www.thebalance.com/claiming-same-dependent-audit-risk-3193030
