I have an old Samsung AT&T phone that I hope to take with me on a trip overseas. Research says it’s compatible with the phone system where I’ll be. It will certainly need a SIM card that allows service there.
It’s currently locked to AT&T, and will need to be unlocked. I’ve obtained an unlock code from AT&T - directions are: Insert new SIM card, and turn phone on. When the message “Your phone is currently locked - enter unlock code:” appears, enter the 8-digit code and all will be right.
My notion is that I should complete this unlock step before I depart - I’m not sure if some sort of contact with an AT&T network will be necessary for this to work. My first question: Is this correct?
Assuming it is, I’ll need to obtain a non-AT&T SIM card to complete the unlock process. Suppose I just borrow one for a moment from some cooperative non-AT&T friend? Will that work, or is there a chance that when he puts the SIM card back in his phone, problems ensue?
I’m not 100% certain of AT&T’s current policies, but they will probably unlock it for you gratis if you visit a store. otherwise, you can pick up a prepaid sim in an airport (presumably when you leave) and use that.
That’s the plan. When the phone detects a non-AT&T SIM, it will ask you for the subsidy unlock code. There’s no communication with the AT&T network during this process.
The reason to do it before leaving is to be able to easily reach AT&T customer service in the event of a problem. Getting to 800 numbers from overseas can be problematic at best, you’ll be paying for the call, etc.
It should just work. Note that if you do a master reset/clear on your phone while the other person’s SIM is installed, it may clear any phonebook entries stored on the SIM (phones can store to local memory, SIM, or both).
I keep a bunch of random SIMs of different form factors around so people can verify their unlocked status. The first 3 I pulled out just now are mobi4U (Vietnam), Maroc Telecom (Morocco), and some random prepaid one from Portugal.
The only thing I’ve seen go wrong with the “insert another person’s SIM card” is if you are putting it in a something that needs a special data plan, and their carrier decides they should be paying extra. I did that to myself coming back from Costa Rica - I had my personal SIM card in my wallet, but was carrying a spare Blackberry as a throw-away phone in case of trouble. When I landed in Miami, I put my personal SIM in the BB to check voice mail. AT&T noticed and added a BB data plan to my account…which they removed after I complained.
But fundamentally…yeah You can just put someone else’s SIM card from another carrier in to trigger the SIM unlock message, and it’s a good idea to do so before you go on your trip.