Can iphone 4s from any career be unlocked for T-mobile?

I just want to know if the iphone 4s from any career ( like AT&T, Verizon, Sprint… ) be unlocked for use on T-mobile GMS?

Yes it can but only the 4S (not the 4). You will also need to either cut your SIM to fit the microSD slot or Tmobile will charge you for a micro SIM card.

The 4 can be unlocked any iPhone can be unlocked for tmobile as long as it is GSM. I don't know if tmobile sells micro sim cards
You can always cut yours

Verizon will not cos it is cdma network, not gsm.