@RobertB4444 wrote:
If you are legally separated as of the last day of the year then you can file as single.
If you are married but didn't live with your spouse for the last half of the year and you have a qualifying child you can file as head of household.
If you must file married filing separately and you do not know your spouse's AGI and can't get it from them then yes, you should enter zero.
"If you are legally separated as of the last day of the year then you can file as single."
This is difficult. You must be "Legally separated from your spouse under a divorce or separate maintenance decree" according to state law. I have never actually seen an example of a state law where the IRS accepted legal separation as being equal to unmarried (for example, if the law allows you to reconcile, no matter how unlikely, you aren't "unmarried" for tax purposes). Certainly it is not allowed for NY and NJ, which I researched extensively. Before you file as single if you are still legally married, check with a professional tax accountant in your state.
"If you must file married filing separately and you do not know your spouse's AGI and can't get it from them then yes, you should enter zero."
The only time the IRS will ask for your spouse's AGI when filing separately (MFS) is for the premium tax credit, but the PTC is disallowed for MFS unless the spouse is a victim of domestic violence or spousal abandonment.
The customer may be asking about a Canadian tax return.
