Hi,
I’m looking for some feedback on this idea I have.
I have an unlocked T-mobile 8320. I live outside USA were I have a local provider with BIS up and running.
I’m planning a trip to USA next month, and I came with this T-mobile Flexpay where it seems I can use like prepaid getting BIS service and all.
What I want to make sure is:
• That I can have two BIS services in two different providers linked to the same PIN or IMEI
• Is there someone using T-mobile Flexpay with BIS service? Can I just cancel it after one month? No cancelation fees?
• Using a T-mobile GMS chip won’t lock my phone again
Thank you for the feedback…..

Once a phone is unlocked, it cannot be relocked. It's not possible in any way or form.

Not even upgrading OS release downloaded from t-mobile website?
Thank you...

Umm, read it again...
No, a PIN can only be registered with one BIS service at a time. You would have to de-register with one before registering with the other. There's a chance that registering with the new one would de-register, not sure. But you'll have to register with t-mobile and resend all service books, and then do the same thing with your original carrier when you go back - at an absolute minimum.

Ok, let’s say it doesn’t do it automatically, how do I de-register and register manually?

Is there any chance when I come back home that I might have troubles going back to my regular provider?

Thank you for your answers....