Ex wants child's social security #

I’m pretty sure I already have the answer to this question, but wanted to ask to be sure.

Ex and I have been divorced for almost a year, I have SOLE legal and physical custody. NCP (father) has only seen our child for a total of 1 hour in the past year. The divorce decree says that joint parental responsibility would be detrimental to my child. My ex is also a drug addict (I promise there is a reason I mention this). Today, he left me a voicemail saying that his tax person (that probably doesn’t exist) said that he needs my son’s social security number so that he can claim him for 1/2 the year. I know that you can’t claim a child for 1/2 a year, which is how I figure the tax person doesn’t exist. Anyway, I know that I get to claim my child because 1. I am the custodial parent and 2. there is no court order saying that he ever gets to claim him (no alternating years or anything), so it would default to the IRS guidelines which state that I get to claim him based on him living with me 365 days out of the past year.

So, my question: Do I have to give him my child’s social security number? I am afraid that he will not only try to claim him on his taxes (which he clearly stated he intends to do, but is not entitled to do) and cause a delay and/or audit (I can quickly clear up the issue with the divorce papers, but it would suck up my time), but that he will also try to obtain credit in my son’s name in order to get drugs. He is trying to say that he has a right to have it, but I just don’t see how it would be wise to give it to him…I could see if we had joint legal custody and he needed it if we switched tax years to claim him, but we don’t…and since he is not allowed to be alone with him, he has no need to have it to try to get him insurance or anything else that might possibly need his social.

Thank you in advance!

I am not an attorney —

I do NOT believe you have to give him your child’s social security number. He has no legal right to the child at this point and you are correct that he is not eligible to claim him on his taxes unless you have an agreement stating otherwise.

I wouldn’t give it to him-He has no need for it. If you both claim your child for tax purposes it will trigger an audit.

Thank you!

If he does get his hands on it and files also, I’m okay with it because I know that in an audit, they will see that I was legally entitled to claim him. Of course, it would still suck, but I won’t be afraid of it going against me.