Buying a phone off contract. How do I "connect" it to AT&T?

[ibex333]

I am strongly considering selling my iPhone 4s and buying a Galaxy SIII from e-bay or here on the forums. If the iPhone had a sim card, or one that I could access, it would be no problem. But I cannot open the iPhone and I never heard of it having a sim card. When I originally got it, I had to enter some sort of a code, and I had to call ATT to activate it.


So how am I supposed to do the switch? Call AT&T, ask them to disconnect the iPhone and connect the Samsung? This might be very obvious to some, but I never bought a phone without a contract before, and I want to make sure I am doing everything correctly.

Thanks.

 

[Suspicious-Teach8788]

The iPhone 4S has a SIM card:

http://webtrickz.com/how-to-insert-sim-card-in-iphone-4/

You should be able to go online once you pop that SIM into the SGS3. Is iPhone 4 Micro SIM? So is SGS3? You should be able to go online at that point. If you need to call AT&T you provide your IMEI # from the Settings => About => Status menu for your SGS3.

 

[Radeon962]

Just make sure you buy a AT&T branded phone or an international version and take both phones into an AT&T store. They will set it up. I went from a galaxy s2 to nexus to HTC one X international to HTC one X AT&T branded to my current phone a galaxy s3 AT&T branded as I have LTE in my area. Each time I just stopped by and told them I was switching phones and they take care of the rest. As long as you have a contract they will take care of you.

 

[ibex333]

The iPhone 4S has a SIM card:

http://webtrickz.com/how-to-insert-sim-card-in-iphone-4/

You should be able to go online once you pop that SIM into the SGS3. Is iPhone 4 Micro SIM? So is SGS3? You should be able to go online at that point. If you need to call AT&T you provide your IMEI # from the Settings => About => Status menu for your SGS3.

Thanks! Didn't know!

 

[VashHT]

Meh don't waste your time going to the store, just swap the sim yourself. Like DLerium said they're both micro sim so you wan't need to make and modifications to it or anything. Just pop it into your SGS3 and it'll be good to go. I've done this many many times on ATT with a lot of different phones.

 

[s44]

The T-mobile S3 will also work fine on AT&T, though you'll have to unlock it (plus no LTE).

 

[gorcorps]

Meh don't waste your time going to the store, just swap the sim yourself. Like DLerium said they're both micro sim so you wan't need to make and modifications to it or anything. Just pop it into your SGS3 and it'll be good to go. I've done this many many times on ATT with a lot of different phones.

This is NOT true when going from iOS to Android or vice versa. It's fine if you keep with one side or the other, but they handle voicemails in different ways and you need to tell AT&T that you're changing phones for them to set it up right. You don't necessarily have to go to the store, but you should still call them

 

[zerogear]

You can add your own APN into android phones. But my off contract phone from UK handles with APN just fine when I put in my AT&T Sim card, I don't think it's a major issue, but if you run into issues, xda has a lot of information on what APN information you need for AT&T.

 

[dagamer34]

The one thing you must absolutely do is call AT&T and have them move you to an LTE plan. This will require you to give them the IMEI of the new phone you get.