Can you use a cell phone from another company?

I just upgraded my cell phone on the sprint network and my old one is sitting idle. My mom is need of one but she is on Verizon. Is it possible for her to use my LG Muzic by just swapping the sim card?

Many phones are locked in to their service provider, and have to be unlocked. Still, you can go online and find out how to unlock them, and, though it may cost a bit of money, it’s still going to be cheaper than buying a whole new phone.

If your LG phone has a SIM card then that mean’s it’s GSM and Verizon is CDMA. Incompatible technologies. However, I thought Sprint was also CDMA (although that in itself does not mean its phones would automatically be compatible with Verizon). Are you sure your phone has a SIM card, and not just a data card?

In general the only thing you can count on is being able to go from one GSM network to another, like AT&T to T-Mobile, providing the phone is unlocked.

How can I tell the difference between the two cards?

What is printed on the card? If it has a storage capacity on it, like 2G, then it isn’t a SIM card. A SIM cardwill often have the service provider’s name on it. A data card will have the manufacturer’s branding with no mention of the service provider.

Sprint is CDMA, however some of their phones come with a GSM SIM for roaming internationally. But I can’t find any reviews that note the Muziq coming with a SIM card. It does have a MicroSD card for removeable storage, but that’s not the same thing.

At any rate the SIM isn’t used when on either Verizon or Sprint’s networks. Theoretically, a Sprint phone could be used on Verizon if the phone covers all of Verizon’s frequencies. Well, you’d also have to unlock it first. Sprint may or may not provide an unlock code depending on the day of the week, phase of the moon, etc.

Wasn’t there a law or regulation passed that they have to unlock the phone if you have fulfilled your contract term? Foggy memory on that.

The regulation allows the owner of the cell phone to unlock their cell phone once they completed the terms of service. However, the regulation neither requires the provider to unlock your phone nor did it actually give permission for a third party to unlock the cell phone. Of course, this makes unlocking your cellphone a bit more difficult.

First: Let us cover GSM.

AT&T and T-Mobile use GSM. In GSM system, there’s a card called the SIM that stores the account information. The phone can also contain a lock that prevents non-company SIM cards from being used on that phone. AT&T does this, T-Mobile does not. Therefore, you should be able to take a T-Mobile phone and put in a SIM card from AT&T and use it, but this doesn’t necessarily work the other way around. AT&T has begun using unlocked tri-band phones. This allows you to take the phone and use it in foreign countries. You could also take a T-Mobile SIM card and use it in these phones.

AT&T iPhones are locked to AT&T and you must get a special “roaming SIM card” from AT&T to use that phone in another country. I don’t know if AT&T will unlock your phone if requested. However, you can usually go into any third party cell phone shop (not company stores) and find someone who’ll unlock your AT&T phone for T-Mobile service (visa-versa isn’t needed).

Now with CDMA:

Verizon and Sprint use CDMA which is incompatible with T-Mobile and AT&T. You cannot use an AT&T or T-Mobile phone on a Sprint or Verizon network.

Even worse, the phones themselves are connected to a particular network and locked to that network. If you have a Sprint phone, you can in theory go to a Verizon network, but Verizon won’t allow it, and visa-versa. You must get your phone from Verizon or Sprint.

Also remember there are other issues involved too like frequency (U.S. GSM phones use a different frequency than European phones) and other network issues.

Fortunately, GSM and CDMA are going over to a new system called LTE which should make all phones more compatible with each other and prevent a company from completely locking out a particular phone from their network.