I want to itemize deductions and my spouse wants to take the standard deduction. Is that allowed when filing as married but filing separately?
No. When a married couple flies separate, if one of your itemizes then both must itemize - even if the itemized deductions of one is ZERO.
If one takes the standard deduction, then both must take the standard deduction even if the itemized deductions of one would be higher.
Also, if we both itemize, how do we split up the mortgage interest, state income tax paid in 2021 , and other deductions?
Split right down the middle.
Also note that when filing separate, both of you lose deductions that you might otherwise qualify for if filing joint. For example, you both lose any education expense deductions.
Additionally, your SALT limits are cut in half for each of you. If filing joint your maximum SALT deduction is $10K. When filing separate, that's cut in half to $5K for each of you.
You can potentially lose quite a lot in deductions and pay significantly more in taxes when a married couple files separate.
