This SE is the most applicable I think because it is in the context of business (renting) and personal finance (permanent address) logistics, even if mainly about mail.
A friend bought a property in the U.S. and eventually moved to a different nearby city for work but kept the house. They don't have any other family or housing in this part of the world, so they prefer to keep the house. Also for that reason, they're thinking to keep their house's address as their permanent address for this phase of their life, using it for key documents & services. They don't have an alternative permanent address, only temporary (likely <3yr, maybe even <1yr) rental address. Is it okay to use a property one is renting as one's permanent address, if it is the only property one owns?
On the one hand, the address they own is indeed their most permanent address. They might move back there eventually, or at least expect to own it a few more years before selling. Even if not their residence, it is still their property they are responsible for and maintain control over to some extent.
On the other hand, they don't live there and someone else does. The renter will be burdened with their landlord's mail, and while that's not a major burden it still presents potential issues: the renter could get annoyed with it, and it could lead to key and confidential documents leaving this friend's control.
For mail pickup, this friend arranges for mail pickups from the tenant, by either themselves or other friends who commute between this friend's current & permanent address locations. This is a little combersome but has worked for them so far.
The only alternative I've thought of is to open a PO box and maintain that until they have a more permanent residence. That's a $100-200/yr cost which isn't too bad, though this friend is trying to keep a tight budget. The rental covers mortgage and (hopefully) maintenance, without much expected profit. A PO box also might not be a valid suggestion, as some services may require a residential address and won't accept a PO box.