I'm currently a tax resident in Washington, a state with no state taxes. I have a Washington drivers license and am registered to vote in Washington. I'm taking a year sabbatical to move to a different country and I'm planning on ending my lease in Washington. (This is essentially a trial run of expatFIRE.)

While I plan to use a mail service for mail delivery, I have a trusted family member who lives in Florida and I am considering using that address as a residential address for financial institutions.

This may be a stupid question, but would this cause any problems with my financial institutions, or is it strictly necessary to use a residential address that is in my state of residence? Does anyone have any experience using a address of residence of a friend or family member that is outside of their current state of residence?

Thank you.