Well, this year my spouse is not a NRA so we filed differently since last year. For tax year 2020 (filed in 2021) and 2021 (filed in 2022) we used Taxslayer with no problem for MFS as NRA with no SSN or ITIN; so unless they've made changes to the software that no longer allows for that, or the IRS changed rules since then, it should work. On a side note, I believe it allows you to open a free account and fill out the forms for free and even possibly file for free (depending on various factors) so I would recommend trying it and see.