Married filing as single, don't know spouses ssn

[sass1989]

Is there anyway to bypass this?

[Opus 17]

Married filing separate.

Leave the space blank, print your return, you can't e-file.  When you mail it in, attach a written statement that explains you don't have your spouse's tax number and give her name, last known address, date of birth, and phone number, so the IRS can try to match her up in their records.