Head of household requires that you provide care in your home for a qualifying person, usually your dependent child. It doesn’t just mean that you are the “head“ or main breadwinner of your household.
You should have been asked for the SSN all along if you were filing MFS. Income information is only required to calculate your subsidy if you bought a Marketplace health insurance plan (Obamacare). If you did not use Obamacare with a subsidy, you should be able to enter zero, or leave it blank. If you used Obamacare with a subsidy, you will have to make your best guess.
You might also be asked for a spouse‘s income if you live in a community property state. However, if you have been separated for a long time, your income is probably not considered “community property“ because the marital community probably ended when you separated. If you just moved into a community property state, that might explain why you have not been asked before. If you don’t have community property with your spouse, you can probably enter zero. You may want to double check with an accountant in your state.
