I was married in 2024, currently divorced. I don’t have my ex’s SSN for my taxes. Can I file without it?

[sarah-merritt98]

We were married as of December 31, 2024, so I had to add him while doing my taxes. We got divorced earlier this year, and I filed separately, but I’m still being asked to provide his SSN, which I don’t have. How do I continue without it?

[xmasbaby0]

Were any of your past returns--like 2023 or earlier--filed jointly?   Did you try looking at your old returns for the SSN?  And....your "ex" needs your SSN just as much as you need his so that he can file MFS.   Is it too contentious to just give each other the SSN's?