Unlock and load!

December 24, 2006 9:09 PM

What could stop me from using an unlocked GSM phone with a Tracfone SIM card?

A couple of years ago, I was first introduced to the world of prepaid cell phones by two friends who use T-Mobile. It was kind of cute that they'd switch their phones constantly by switching out the SIM cards between them. T-Mobile isn't available in my area, but about a year ago I needed to get rid of my monthly Sprint service so I picked Tracfone. I was told that Tracfone won't allow you to use a phone that they don't sell you directly. Let's face it, all those models basically suck.

Aside from the fact that I wouldn't be able to use some of the features of a better phone without a monthly service (like web access), what could keep me from using my SIM card in a random unlocked phone that I buy (that Tracfone didn't sell me)? Could Tracfone block my service somehow? Since you designate your ESN/IMEI when you reload on minutes, wouldn't I just need to keep around the original phone so I could slip the card back in when necessary?

What could/should stop me from upgrading my phone?

posted by fujiko to technology (6 comments total)

Why, Tracfone of course.
posted by cillit bang at 9:24 PM on December 24, 2006

Yeah, providers can tell what handset you're using and deny service if they don't like it. T-Mobile is the only major GSM provider that actually allows you to use an unlocked phone, IIRC.
posted by delmoi at 10:34 PM on December 24, 2006

One of the reasons that the service providers want to limit the number of brands of handsets used with their system is interoperability. Before they approve a handset, they test it extensively with their infrastructure to make sure it works properly and won't cause any problems.

Another reason is tech support. Whether it ought to be like this or not, a certain percentage of people using outside handsets will expect the service provider to answer questions about how to use the phone and provide other kinds of support. Part of what the service provider does when they approve a model of phone is to train their tech support people so they can support that model of phone. That can also include acquisition of tools for the service centers (e.g. custom cables and computer programs to do firmware upgrades).

But for outside models, the tech support person may have no more clue than the confused customer does -- and, whether it ought to or not, this often makes the customer angry.

It's less of headache for the service provider if they can limit the number of models of handsets on their system, which they have to support. Tech support and interoperability are already enough of a headache without the added burden of uncontrolled use of outside models.
posted by Steven C. Den Beste at 11:20 PM on December 24, 2006

I hope nobody minds if I ask a piggyback question: I have a motorola RAZR. As far as I can tell, it's unlocked. It was bought in the US to use on a trip in Europe, where it performed well enough (oddly, it came with a British plug with a US adapter). However, when I stick my t-mobile SIM into it, it doesn't seem to get any reception, although it doesn't reject it outright with an error. My first thought would be that it's running on the wrong set of frequencies, but in the settings it is set to 850/1900. Anyone know how I can troubleshoot this beastie?
posted by alexei at 1:01 AM on December 25, 2006

delmoi, you can use an unlocked phone on Cingular (presuming it has the proper frequencies), but they won't provide support for it. Other than Tracfone, I don't know of any GSM provider that actively prevents you from using any phone you like.

In Tracfone's case, the phones have special firmware, and as far as I know, you can't use a phone without the special firmware with a Tracfone SIM.

I'm just speculating, but the SIM probably has a program that runs on startup that checks the firmware.

FWIW, Cingular (presuming it's available in your area, of course) does have a couple of different types of prepaid, but they're probably not cost effective for you if you're happy with Tracfone, unless you mostly talk after 9pm and on weekends.

alexei, if it was locked, it would tell you..the RAZRs I've seen do anyway.
posted by wierdo at 7:22 AM on December 25, 2006

What weirdo said about Cingular allowing non-Cingular phones. My work phone is on Cingular and its sim works fine in my unlocked K800i which isn't available in the US. Cingular's website does say somewhere you have to use one of their phones, but I think that is as Steven said, to reduce support calls.

I have my personal service through T-mobile and haven't bought a phone from them in years.

When I have to deal with Cingular and T-mobile with the non-supported phones, the first thing they will do is blame the phone. After that, they'll be quite helpful in providing generic instructions on the issue.

alexi - it could be a bad SIM. When I changed phones once, the new phone would freeze after it's boot sequence. It would still work fine in other phones. At a t-mobile store, I got a new SIM card and I was good to go.
posted by birdherder at 8:12 AM on December 25, 2006