Assuming you want to file MFJ, you can create one file. The real question is whether there is a permanent home in the picture where everyone intends to live in the future. I had several spouses move out of state when the GM plant closed. One spouse stayed in the home (CA) and worked there. The other moved to MO and worked in KS, with full intention of returning to CA when he retired. One file- Federal with 3 states. CA gave a credit for MO and KS and I don't remember exactly which of the MO or KS reciprocated. Net result is the client will end up paying the higher of the states involved, but MFJ is sure much easier.
Residence and Domicile are different.
Here is California's point of view:
"Who Are Residents and
Nonresidents
A resident is any individual who meets any of the
following:
• Present in California for other than a temporary or
transitory purpose.
• Domiciled in California, but outside California for a
temporary or transitory purpose. (See Section L,
Meaning of Domicile, on page 9).
A nonresident is any individual who is not a resident.
A part-year resident is any individual who is a California
resident for part of the year and a nonresident for part of
the year.:
"L Meaning of Domicile
The term “domicile” has a special legal definition that is
not the same as residence. While many states consider
domicile and residence to be the same, California makes
a distinction and views them as two separate concepts,
even though they may often overlap. For instance, you
may be domiciled in California but not be a California
resident or you may be domiciled in another state but be
a California resident for income tax purposes.
Domicile is defined for tax purposes as the place
where you voluntarily establish yourself and family,
not merely for a special or limited purpose, but with a
present intention of making it your true, fixed, permanent
home and principal establishment. It is the place
where, whenever you are absent, you intend to return. The maintenance of a marital abode in California is a
significant factor in establishing domicile in California.
Change of Domicile
You can have only one domicile at a time. Once you
acquire a domicile, you retain that domicile until you
acquire another.
A change of domicile requires all of the following:
• Abandonment of your prior domicile.
• Physically moving to and residing in the new locality.
• Intent to remain in the new locality permanently or
indefinitely as demonstrated by your actions."
Answers are easy. Questions are hard!
