dependent deduction for child who file own taxes

[KazelBritz]

My child aged 26 made under $4,000 in 2019 and filed his own taxes already, but did not check off box that I (his parent) could claim him as a dependent. He received a small refund along with stimulus check. I'm not doing my return. I provided more than half his support and he lived with me the entire year. Can I still claim him as a dependent and if so, does he then need to amend his return to notify IRS that he can be claimed on someone else's return? Will this adversely affect him (will he  owe back funds he received)? Is it worth my claiming him and amending his return?  

[BMcCalpin]

"I'm not doing my return. " What does this mean? That you haven't done your return yet, or that you don't have to file?

If you don't have to file (presumably because of insufficient income to be required to file), then claiming your son as a dependent won't do you any good at all.

If you in fact do have taxable income, then the most taking your son as a dependent is worth to you is a $500 deduction. Look at your marginal tax rate (say, 12%), and such a deduction is worth only 12% of $550, or $60 in tax savings. Of course, the higher your marginal tax rate, the more of a benefit there is.

As things stand right now, because your son did not indicate that he could be taken as a dependent, you cannot e-file while claiming him as a dependent. 

As to whether or not your son would have to pay back some or all of his refund if he changes his status to dependent, I don't have enough information, but the odds are that he would owe something. As for his stimulus money, it would make sense that he would have to repay that, but the rules are so new and the process so haphazard, it's not clear to me how this would happen.

I suggest you run (not file) your return twice - once with him as a dependent and once without. My guess is that it won't make a large difference to you - and note that since you can't e-file, you will have to wait months for any refund anyway, since the virus has shut down a lot of manually processing at the IRS (like filing on paper).

Then you can decide if it is worth the hassle for you and the possible expense to your son.

[Opus 17]

I think “not” is a typo for “now” — the taxpayer is now doing his own return.  

if your child has less than $4200 of taxable income and you provided more than half his total support, you are entitled to claim him as a dependent. If you do, you will have to mail your return, because his return will block you from e-filing if you claim him as a dependent.  Then, the IRS will send letters to both of you to start an investigation of the duplicate claim, are usually about 6 to 9 months after you file, but it might take longer this year because of the coronavirus shut down. You and your child will each have to provide evidence about whether he can be claimed as a dependent by you or not. If the IRS rules in your favor, he would be required to pay back any part of his tax refund that came from not checking the box that says he was a dependent. He may also have to re-pay the stimulus payment, although this is unclear simply because it is so new and there haven’t been any adjudications of improper dependent claims yet.

The question for you is, do you want to claim him as a dependent for a $500 credit and launch an IRS investigation.