Hi girlsmom -
Not sure exactly what you're thinking about doing.
In general "PTO" is a catch-all acronym for independent parent groups. While the acronym PTO is the most commonly used acronym for independents, your current PTC would also be considered a "PTO" for the sake of discussion. A simple name change wouoldn't present you any problems. There's likely some procedural paperwork with state and IRS to finalize the name change, if you want to make it.
I'm thinking that maybe you're referring to joining the National PTO Network. If so, you should know that National PTO Network affiliation is open to all groups, regardless of acronym. We have several PTAs that are affiliated with NPN and we have tons of groups like PTCs and PCCs and the like who are affiliated, as well.
The word "join" is sometimes a bit confusing. You're not really "joining" NPN so much as your choosing to take advantage of NPN benefits for one year. The best analogy is AAA (the auto club), where they call it "joining" but where you're really paying for a bunch of really nice services for one year. NPN is like that. There's the insurance discount, the expert guides, the member's-only web access, the quarterly NPN newsletter (difft than the magazine), the NPN grants program, the forms and tools, etc. -- all for just $179 per year.
There's no complicated process for getting in and certainly no complicated process for getting out. If your group likes the services you're getting, you stay (just like AAA). And if you don't, then you don't renew (and we try our tails off to get better).
More details here:
www.ptotoday.com/npn
Hope this helps.
Tim