Can my sons dad (non custodial) claim our son on taxes without my permission?

[aaron-garrison25]

My son has lived with my boyfriend and I full time for a little over a year now, and spends maybe 4 nights a month at his dad's house. I am a stay at home mom, and my boyfriend provides all financial support for me, my son, and our 2 children that we have together. My boyfriend will be claiming me and our 2 children on taxes, but my sons dad says that since I didn't work, that automatically means that he can claim our son, even though he lived with me, and my boyfriend provided all financial support. Can my sons dad claim our son on his taxes without my permission?

[Hal_Al]

No. The non custodial parent still needs the custodial parent's permission, on IRS form 8332, even if the custodial parent is not filing a tax return, because she didn't work (or any other reason).

But the biological father  will get a much bigger refund than your BF will. At most, the child is worth $500 to the BF, maybe less. He's worth $2000 to the father (maybe less).

There are two types of dependents, "Qualifying Children"(QC) and standard ("Qualifying Relative" in IRS parlance even though they don't have to actually be related). The child may qualify as your BF's dependent, but because he is not related, he cannot be a qualifying child for the earned income credit or child tax credit.There is no income test for a QC but there is an age limit, a relationship test and a residence test. 

On the other hand, the biological father can claim the Child tax credit, but still not the Earned Income  Credit (because the child does not live with him).