Can you buy an unlocked GSM phone and use the Sim card from your old ATT Cellular Nokia GSM phone without Cingualr having a problem with it and having to sign a new contract?

Answer:

GSM Phone

As long as your carrier uses GSM (AT&T, T-Mobile) and SIM card works in your current device you can use an unlocked GSM device. This only makes Voice service work however. If you want data services to work you will need to get the data settings from your carrier and will most likely have to contact the device manufacturer to get them entered correctly.


If an Unlocked GSM device states it is 3G or 4G compatible it does not mean that you will be able to use that part of your carrier's network. For instance AT&T and T-Mobile use different bandwidths for 3G/4G service not all devices will be compatible.


As always, before you buy an unlocked phone you might want to call your provider to make sure it has the right capabilities for you.
Contributor: Rose
First answer by Crystal. Last edit by Rose Hurban. Contributor trust: 0 [recommend contributor recommended]. Question popularity: 32 [recommend question].