I don't know my husband's social security number

[llbrown1995]

I'm in the middles of divorcing my husband whom I've been separated from since Nov 2015 and don't know any of his personal info save for his birthdate and name.

[Marketstar]

If you are filing Married Filing Separate, you will need to file a paper return, and write in Unknown in his Social Security number field on the top right of the tax form.

You should also attach a short note explaining why his social security number is unknown.