Tax trouble HELP

[xXMeowzersXx]

Long story short, I got my years mixed up. 
My ex-spouse and I have a tax agreement where we alternate years with him getting the even numbers and I get the odd numbers. 
I got my years mixed up and didn’t claim my son last year, so neither did his father.

Well, this year I claimed him on taxes.. and already got mine back in February. His father just tried to file his and claim our son because it is his year and couldn’t. 
He talked to his accountant, who said I could file an amendment to move my son off this year’s taxes to last year’s taxes because neither of us claimed him as a dependent. 
So I’m posting here to ask if that is even a possibility or true. 
This is the first time I’ve ever done anything remotely wrong so I am panicking! 

[RachelW33]

Yes, your ex-spouse's accountant is correct.

You need to Amend your 2024 Federal and State Tax Returns to remove your son AND Amend your 2023 Federal and State Tax Returns to add your son as a Dependent.

In order to avoid any interest or penalties for your 2024 tax returns, you should file and pay the balance due with your Amendment by 4/15/25. (This is because you received more than the refund you were due).  Generally you have up to 3 years after you filed the original return to file an amendment.  Please see What is the deadline for filing an Amended Return? for more details.

Please see these TurboTax Help Articles for instructions on how to Amend each year:

• How do I amend my tax return for this year?
• How do I amend my tax return for a prior year?

[xXMeowzersXx]

Oh man. 
So the “balance” would be whatever I got for my son this year? So whatever I pay it back and will get last years back? 

[RachelW33]

Yes, you will basically be paying back what you got for your son in 2024 and then receiving a refund for adding him to your 2023 return.

[robtm]

Yes, the accountants advice is correct. You file an amendment for 2024 to remove your child and one for 2023 to claim him. A simpler way might be for him to file the 2023 amendment to claim him and then you go back to your original agreement to claim him in alternate years.

[xXMeowzersXx]

He said he couldn’t do it because he has multiple businesses that would affected. 
I would love for him to do last years and not have to pay back that money I don’t have but unfortunately it’s looking like I’m screwed either way lol. 

[JohnB5677]

As it stands you will have to file amended returns for both 2023 and 2024.

• You will get a refund in 2023 and have to repay 2024.
• Your Ex will mail his return, and if your 2024 amended return is not completely processed you will both get a tax notice
• The notice will be explained by telling the IRS that you filled an amended return.

[xXMeowzersXx]

I talked to my accountant this morning. 
He explained that it would be easier for him to file an amendment for 2023 and add our son as a dependent. Than it would for me to file an amendment and send all that money back with the 50/50 possibility of the our sons SSI number getting flagged and potentially no one being able to claim him, in result, me losing the $4k I sent back. 
He did however tell me that because we don’t have an agreement with the IRS that even if I did claim him there’s nothing anyone could do because we’re both the parent. 
He seems okay with claiming last years and being able to claim next year. So fingers crossed it all goes well. 
Thank you all for your help!!