I read on Page 4 of FTB Pub. 1031 2019 (mirror) (I italicized the important passages):
[Section E:] 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.
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.
and:
[Section L:] Meaning of Domicile
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.
Does this mean that an individual who hasn't been in California in 2019 but is domiciled in California throughout 2019 is a California tax resident?
I also read on https://www.lexisnexis.com/legalnewsroom/tax-law/b/stateandlocaltaxation/posts/california-residency-for-income-tax-purposes:
As a general rule, California imposes a tax on the entire taxable income of all California residents. [Cal. Rev. & Tax Code § 17041(a)]. Section 17014(a) of the California Revenue and Taxation Code defines a "resident" as either "every individual domiciled in this state who is outside the state for a temporary or transitory purpose" or "every individual who is in this state for other than a temporary or transitory purpose." ...
