I am a travel nurse with my home base in Tucson AZ. My name is currently on an apartment lease in Tucson but will be moving in with a friend (who is also in Tucson) in May. I will be paying her monthly rent through Venmo, but I will not be adding my name to her lease nor will my name be on her utility bills since this is all already established and she is already living in her house. I currently receive untaxed living stipends through my travel contracts and want to ensure I can prove my new permanent tax address appropriately.
The best way is to update your driver's license and voter registration. If possible have utility and/or credit card statements sent to the new location. You could also ask your friend to provide an affidavit.
The general rule of thumb, especially when it comes to taxes, as well as some government benefits, is this:
If it's not in writing, then it did not occur.
Period.
You would need something in writing, that would be recognized in a court as legally binding, to prove that what you say is your primary residence, is "in fact" your primary residence. The two most common things I'm aware of off the top of my head, is the address on your driver's license, and the address on your voter registration card.