Will T-Mobile work on any iPhone4 baseband?

[rfs2005]

The title says it all... I will soon be getting my old iPhone4 unlocked through the new AT&T policy. Part of the procedure requires me to backup/restore with iTunes. Will updating the OS (and baseband) to the latest version work if I plan to use my newly unlocked phone with T-Mobile? Jailbreaking is not important to me right now, at least not at the moment. I just want to make sure T-Mobile will work on newer basebands, as it is nearly impossible to downgrade basebands if I make a mistake by upgrading to a newer one.

Thanks!

 

[Sine Qua Non]

1. You don't really need to do a full restore for the AT&T official unlock to take effect.

2. Any baseband will work on T-Mobile if the phone is officially unlocked.

 

[heyyitzmelissa]

Don't restore, just use Deactivate option in redsn0w