Can you convert verizion to tmobile in an iphone 4?

Buying unlocked iphone 4 are alot of money can i just buy a verizion/att/sprint iphon and convert it to tmobile cheaply or on my cp?

Verizon and Sprint Iphones will never work on ATT or Tmobile… Apple/Verizon/Sprint has blocked all GSM carriers in USA. Only GSM carriers SIM cards in other countries will work in a VErizon/Sprint Iphone…

if you want an Iphone on Tmobile, you will have to unlock a ATT iphone OR buy a unlocked ATT iphone

Not Verizon or Sprint because their phones are CDMA and can't be used on T-Mobile.AT&T phones can be unlocked but they only do it themselves if the phone is out of contract. If you got one now and cancelled it you'd pay early termination fees that would offset the initial savings of a contract phones.

The reason the phones are so cheap is because you're agreeing to a 2-year commitment with whatever company and more or less paying the phone off over that time.