I dont know my spouses social

[samantha-miller2]

No clue on his social

[Marketstar]

If you are filing Married Filing Separate and do not have your spouse's Social Security number, you will need to file  a paper return and write Unknown in the Spouse’s social security field in the top right hand corner of the 1040 form.

You should also attach a short not explaining why his/her Social Security number is unknown.