The tax law says that he must enter the spouses SSN on a Married Separate return. The IRS can impose a penalty on you for failing to provide it.
If you don't file your return and pay your tax by the due date, you may have to pay a penalty. You may also have to pay a penalty if you substantially understate your tax, understate a reportable transaction, file an erroneous claim for refund or credit, file a frivolous tax submission, or fail to supply your SSN or ITIN. If you provide fraudulent information on your return, you may have to pay a civil fraud penalty.
**Disclaimer: This post is for discussion purposes only and is NOT tax advice. The author takes no responsibility for the accuracy of any information in this post.**
