Every single bank I apply at has for past two years accepted my UPS Store mailbox address (which uses a Suite number rather than a "mailbox" number) as my mailing address. I did this because I travel a lot and the mailbox at my physical home is not secure and no one is around to sign for anything that must signed for (such as cards that get expedited). I think one bank may have wanted my physical address to keep behind the scenes, but each bank has since allowed me to change my mailing address to the UPS Store mailbox, and once that was changed, each bank I've applied at has accepted that UPS Store mailbox address as "the" address for a new application.