@Hal_Al --
CA and AZ do not have reciprocity in the traditional sense. Residents of those states are not exempt from having to file a non-resident tax return in the other state.
A California resident who works in Arizona may claim exemption from Arizona withholding by filing AZ Form WEC with their AZ employer. But this does not exempt them from having to file a non-resident AZ tax return if they meet AZ's filing requirements for non-residents. See page 2 of the instructions for AZ Form WEC:
https://azdor.gov/forms/withholding-forms/withholding-exemption-certificate
CA has no equivalent rule. AZ residents who work in CA may not claim exemption from CA withholding. The only exceptions to CA's withholding requirements are listed in Section F of this reference:
https://www.ftb.ca.gov/forms/2024/2024-588-instructions.html
An AZ resident who works in CA is not exempt from having to file a non-resident CA tax return, assuming their income exceeds CA's filing threshold for non-residents.
**Answers are correct to the best of my ability but do not constitute tax or legal advice.
