Married Filing Separate

[Christian]

An older retired couple recently married. They lived in different states with her moving to Virginia late in the year. They advised they would file MFS for 2023 which seemed ok to me. His wife reputedly worked for H&R Block in the past and wanted to file her own she said so ok to that. This year the husband comes in with his info only. I advised him that filing jointly would likely be the better option since filing MFS but living together was by my reading of the law not a great idea. He said his new wife had not filed a return in years to which I replied that so long as she fell beneath the filing requirements there was no problem. Two problems occur to me in this matter. If he files MFS can she simply not file assuming her income is below the filing requirement limit ? Secondly in reading the regs on couples with Social Security income filing MFS looks to expose more of that income to tax if the couple lives together which seems odd. I would like clarification on this point as I myself could have misread the regs. As you may guess I have never seen this particular situation in the years I have been in business. 

[BrewOne]

Taxation of the social security with MFS depends on whether or not they lived together.  If they lived apart for all of 2023, they would get the same "base amount" of $25,000 that a Single filer would get.  If they lived together at any time during 2023, the base amount is zero--in this scenario she would probably have a filing requirement.

Ideally, you could plug in all of their income into the software and show them the total tax liability MFJ vs MFS.  But it is their decision and it is not always about what would be saved that year--new couples sometimes find out about their spouse's unpaid liabilities when they file jointly.