Can you used two sim cards on one phone?

I have tried it before with one cingular sim card and one t-mobile sim card. But will cingular let me activate another sim card on the same cell phone that another cingular sim card was activated on? Thanks

Can you used two sim cards on one phone?
u can use 2 simcards on 1 phone from the same carrier. if its an unlocked phone u could use a simcard from another carrier
Reply:no. it wont work.
Reply:yes.go to this link
Reply:nope i don't think so unless you're phone is like reely cool
Reply:I have Suncom and i can change out SIM cards on my phone and they both work as long as its unblocked
Reply:I have Nextel and I can put a Boost sim card in it. In the old Boost phones, you can also put a Nextel sim card. When Boost caught on that Nextel customers were buying cheaper Boost phones and putting in Nextel sim cards, Boost changed their software. A new model of a Nextel Motorola runs for about $350.00. The same phone model that Boost sells for about $200.00. Nextel has a real racket going. My point is that if your phone is unblocked and it's an older model, it may allow you to use two sim cards.
Reply:As long as the phone will recognise both cards then there should be no problem
Reply:yes, but you need to unblock the phone and buy a dual sim adaptor. With the adaptor you can just go to conf. and change of sim.
Reply:If you keep swaping ur sim card.. yes