Figure out where you want to be a resident first. FL, SD and TX are the most popular and you can search many forums for fulltime State of residence or mail forwarding services for lots and lots of information. I was using FL or many years but chose to move to SD for the lower sales tax on a new (to me) RV and the positive comments on all of the mail forwarders in SD. We picked Americas Mailbox but only because we were not going to travel any farther East than Rapid City and I could get everything handled in one location at one time. There are 2 other major providers which also have excellent reputations.