I have a client whose HOR was Oregon and is now stationed in Colorado. He files MFJ with his nonmilitary spouse who lives, works and goes to school in California. Both hold Oregon drivers license and voters card. They own a home in California where the nonmilitary spouse lives and attends college. He has only earnings from Colorado with Colorado withholding and is active duty. His nonmilitary spouse has W-2 earnings from the college she attends in California. In 2019 he changed his SLR to Colorado to get a resident hunting tag and switched it back to Oregon in September of 2019.
Therefore, how would they file for state purposes? Would he file as an Oregon full year resident and file as a nonresident for Colorado just to get his withholding back? Also, since he is filing MFJ and his nonmilitary spouses income is only $3,356 which is below the filing requirement they should not have to file a California return, but claim her income on the resident Oregon return? Any help is appreciated.
California has a good publication. You can see it as html https://www.ftb.ca.gov/file/personal/filing-situations/military.html or pdf https://www.ftb.ca.gov/forms/2018/18_1032.pdf
I sure Oregon has similar pubs.
The way it works in general is you will get a credit in one state for the tax paid in the other. There is no double tax, but a client will likely end up with the higher of the two taxes. If you set up the software correctly it should go fairly smooth. You do need to read carefully to set up the software.