unlock to use with other carrier

[sborn2]

i am a at&t customer. I went threw the steps and got a unlock code so i can use the phone with another carrier while i am over seas. My question is can i unlock the phone and still use my at&t card with out the phone locking agine back to at&t. i am aware that i need another carriers sim card to do the process...but once it is done am i able to switch back n fourth between sims? i don't leave for about a month or so. But i would like to make sure it works

 

[Almeuit]

Once the phone is unlocked you're good to go. You can use any compatible SIM in at.. on the fly. Either your AT&T one or one while you're abroad.