What do I do if I’m separated from my wife (not legally) and have no idea where she is? (She walked out on me years ago and is living on the streets so I’ve heard)

[vazquezchris62638]

I don’t know her SSN, but have to file married filing seperate

[KeshaH]

You'll need to enter a placeholder SSN (such as all zeroes) for your wife so that the return can be properly calculated. The return won't be able to be filed electronically, so you'll have to print and mail it to the IRS.