Deductions & credits

Therefore he should admend his tax return & unclaim those credits I assume? Will turbo tax walk him through this process since he filed with tt? And lastly is it legal or are you allowed to unclaim a dependent and someone else claim her? 

We have a daughter 6 years of age,  she lives with me now but in 2021 she lived with us both the same amount of time, we live a houses away & I've always let him claim her with no problems, until now but I don't want to make things worse. 

I guess I'm asking if it's even legal to unclaim a dependent & someone else claim that Said dependent? 

Because it was a honest mistake it's very vague about the issue but After reading your letter I do lean towards Home dentintion Is not eligible to claim eic or ctc.