Can a gsm phone be linked to 2 different carriers at once?

lightsleeper23 · February 5th, 2013, 12:05 AM

Just wondering, if you have a gsm phone and multiple sims, can you activate it on multiple carriers at once, and swap the sims back and forth? Or does linking the serial # to one make it not work on another? Thanks.

Hadron · February 5th, 2013, 02:14 AM

There is no linking of handset serial numbers to carriers/accountswith GSM - it's the SIM that identifies the account to the network.

However, phones bought through carriers are usually locked to only accept that carrier's SIMs. If you have an unlocked phone however you can swap SIMs as you like, and even with a locked phone you can use a different SIM from the same carrier. That was the reason for the SIM card in the first place

To be clear, there is no "activating" a handset on a network with GSM - just stick the SIM in and you're done.

lightsleeper23 · February 5th, 2013, 03:15 AM

Ok thank you very much. I ask because I got a new T-Mobile phone and I wanted to try a couple different MVNOs, while keeping the accounts active (just only paying for service from one at a time) in case I wanted to easily switch back to a previous one.

Not that I want to do this indefinitely, just for a few months until I find the right one. I just didn't want to try activating a new sim and have any issues because my imei was registered to a different carrier. You think I should have no problems with this?

Davdi · February 5th, 2013, 04:54 AM

My unlocked WFS has been used with SIMS from Virgin, Orange, GT Mobile, Lebara, Vectone Mobile as coverage when I'm in Spain or Italy can be patchy in rural areas. No problems at all.

Hadron · February 5th, 2013, 05:47 AM

I think your only problem might be the phrase "just got a new T-Mobile phone". If it's from T-Mobile it's probably locked to their SIMs, and if "just" means the last 10 days then it will be illegal for you to unlock it yourself, and you will have to rely on T-Mobile to provide an unlock code.

If the phone pre-dates the new law coming in then you are fine to unlock it yourself.

I cannot imagine why the IMEI would be a problem. If you buy a Nexus from the Play Store and stick whatever SIM you like in it it works, you don't need to register the IMEI, and if you put a different SIM in the new network isn't going to refuse the phone because the IMEI has been used elsewhere. It's not like CDMA networks where the handset id number is what is registered to the network, with GSM the SIM is the thing that links the handset to an account. The only time IMEI is a problem is if the phone is reported stolen, when the IMEI will be blocked.

mikedt · February 5th, 2013, 06:35 AM

If you can get a dual SIM phone, that should do what you need. Make sure it's both SIMs active though.

lightsleeper23 · February 5th, 2013, 01:03 PM

It's not unlocked, but I'm only trying to use it on T-Mobile MVNOs like simple mobile, Solavei, straight talk with a T-Mobile SIM...