BIS 3.0 & changing providers

I am in Thailand. How can I tell if BIS 3.0 is active here? Also if I want to switch providers do I have to have current provider clear PIN first or can I just go to new provider and will putting new sim in phone switch PIN to new provider? I heard something about BIS 3.0 (if I am on it) has made switching devices and providers easier. Any info someone can provide on this would be appreciated. I am worried about downtime having one provider close account and clear PIN and waiting until I can activate on new provider.