I stay in one place long term so I use that address.
I have used 3 mail forwarding companies (UPS Store for TN, one that closed in TN and SBI in FL). I am physically in NM and have been for about 12 years.
I will tell you that, in recent years, much of what has worked for others, will not work for "new" people. Things have changed. As someone who has lived in an RV with no house since 2006, what I did the first time (1995-1997) would not work now. Part of what I started out doing, wouldn't work if I were to try to implement it today.
I have a FL address (SBI) that makes the US government and my bank happy and is the only reason I have it. It did not make the state of NM happy. So I use my RV park address (and getting the first address into the system was a PITA). If I didn't have the mail forwarding address, I would have to either use my daughter's house (NM) or my Mom's house (NC). I file NM state taxes. I don't want to have to file NC state taxes as well.
I used to use my daughter's house address but she sold it and I moved a bit too far away, then she got a new house even farther away. My insurance company (Geico... I used to also have National General at the same time on my bus) is happy that my "garage" address is the same as what is on my NM driver's license (my current RV park). My voter's registration is the same as my driver's license. I keep updating my address online for the various places. I've been here for 3 or 4 years but my street address changed (per USPS).
If you use a mail forwarding company, make sure you get one that has a "street address". If they have one, it will be mentioned on their website. Most official places (like banks, IRS, insurance companies) will accept a "street address" from a mailing company. Some have a database of mail forwarding companies and will refuse the address. I had problems with National General Insurance with one of my RV park addresses but not with any of my mail forwarding addresses.
Make sure it is in a state that has no income taxes (one less thing to file every year). If you earn money in a state that collects income taxes, you have to pay out-of-state resident rates (usually double what the in state rates are) and file in each state you worked. It gets harder when you claim residence in a state that collects income because you file your residence state PLUS any other state you made money in. If you under pay according to your state (your residence state has a higher income tax rate), you make up the difference. If your residence state has a lower tax rate than the state(s) you earned income in, that's nice, but you aren't getting a refund.
Make sure the mail forwarding company you choose is in a state that you pass thru every so often. You can only renew an driver's license online a limited number of times (if at all). You will have to appear for jury duty in some states (out of the state is not considered a valid excuse by some states). And then there is voting. You will have to organize that or drop back in the state every so often.
Some medical insurance providers limit where you can use doctors. So you need to check on that.
It's just not as easy as it used to be. The government and other entities want to know where you are at all times. They are afraid they are going to miss out on getting money from you. And various governmental agencies get money from other governmental agencies based on who is where. So they want to make sure you are where they can benefit from you. If "they" can't find you, then you must be up to no good. That is the basis of the the Patriot Act. Thanks to that Act, it has mucked up everything for the nomads of the US.
