 So obviously the IRS needs to have the name and the address. I need an address too. As well as the identification number, the social security number on the tax return. So you've got to print or type the information into space provided, top of the form 1040. Typically, if you are married filing a separate return. Yeah, maybe I'll file a federal income tax return. Enter your spouse's name in the entry space below the filing status checkbox instead of below your name. So remember we talked about the filing statuses before we've got the single, we've got the head of household, we've got the married, married filing separate. So if you're married filing joint, then of course there's going to be a space for the two spouses involved and the related social security numbers. See social security number. If you're filing married filing separate, then the IRS still wants an indication of your spouse so that they could basically check on the other side, seeing if the spouse then filed a tax return.