The IRS rule states that if one spouse itemizes deductions, the other cannot claim the standard deduction. This is designed to prevent couples from unfairly benefiting from both a large itemized deduction and the standard deduction, which isn't possible with joint filing.

However, in situations where one spouse is a U.S. resident and the other is a nonresident alien, and they decide to file separately, the nonresident alien spouse doesn't have the option to take the standard deduction. This scenario doesn't seem to confer the same unfair advantage the rule aims to prevent. Given this context, is the resident spouse still required to itemize their deductions?

PS: While I'm aware that these spouses have the option to file jointly by electing to treat the nonresident spouse as a U.S. resident for tax purposes, they prefer not to do so due to legal concerns.

PPS: I generally do not post non software specific questions only on taxprotalk forum, but we have some experts on nonresidents here who are not frequent on that forum, sorry for the folks who are on both.