First, if you are "NOT" married on or before Dec 31, 2019 and there are no kids involved, then the only filing status available to each of you is *single*. That's it.
Otherwise, for a married couple to file separate will always cost more tax-wise. When a married couple files separate returns, both partners *automatically* disqualify for deductions they would otherwise qualify for if they filed joint. For example, you can't get "any" deductions for education, or the EIC credit among numerous others. Additionally, if one of you takes the standard deductions, then you must *both* take the standard deduction; even if the itemized deductions of one of you is higher. Likewise on the flipside, if one of you itemizes deductions, then both of you must itemize deductions; even if the itemized deductions of one of you is ZERO.
So on the federal tax side for a married couple to file separate, it's practically *never* advantageous to do so. On the state side, if both of you have different states of legal residence and one of those states is a community property state, that not only complicates the separate state returns each of you must file - it also complicates things on the federal return.
In other words, in your case if you two file separately, welcome to the nightmare from which you may never awaken. 🙂
