We are residents of NJ. My child is a college student in CA. Every year, he spends 11 months on campus in CA, and only 1 month elsewhere (NJ, NY, other states). Should he file as NJ resident and CA non-resident, or as CA resident and NJ non-resident?
Generally, college students (dependents on their parent's tax return and non-dependent's) are still residents of their home state until they change their residency. If your student is present in CA for a temporary purpose (college), CA doesn't consider them a resident.
Refer to CA FTB website Residency status for additional information.
Unfortunately, NJ state tax return wants too much taxes out of his college TA earnings even though he spends most of the year in CA. The CA state refund does not offset NJ state tax burden. Why should his CA earnings be taxable in NJ?
Because he is a resident of New Jersey where you claim him as a dependent.
New Jersey taxes everything that a resident earns.