What happens when you change your iPhone SIM card

If you change it for a SIM from the same carrier, nothing happens, the device continues working as before.

If you change it for a SIM from another carrier and the phone is locked to the original, then it will work as a fancy iPod, none of the phone capabilities will be available. If you are eligible for unlocking, note that it entails a procedure to carry out after the carrier does its thing and this may entail having to reset/wipe the phone.

Credit card information is NOT stored on the SIM - no user data at all is stored on an iPhone SIM. Your credit card information is stored on the phone and is encrypted along with the rest of your user data.

Even if you use iCloud Keychain and store credit card and payment information in that, it is on the phone and encrypted. The keychain is sync'd to your other devices via iCloud, but it is encrypted in iCloud as well, and the transmission to and from sync'd devices is also over encrypted secure connections. All user data on the iphone is encrypted as is all data in your iCloud account and all data transmissions to and from your iCloud account are over encrypted channels.

Storing anything on the SIM would actually be counter to iOS's entire security model to protect your data.

Sorry, I was under the impression that it stored the phone number and carrier code. I now realize (thanks to your post) that there is nothing stored there...it's kind of like jewelry for the iPhone. I learn a lot on this forum...hope I'm caught up now.

Oops! I just checked the Apple website. It said, "Like most cellular phones, the iPhone uses a SIM card to determine the phone number, carrier, and features that are available for the account."

I think you need contact them and let them know that nothing is stored on a SIM card, so they'll be caught up, too!

Back up your phone on iCloud or a computer using iTunes (which you should do anyway). My experience with SIM cards is that there is very little stored there (phone number, carrier code, and sometimes contacts).

The Apple website has a lot of information for how to back up your phone, available under the "Support" tab. Also how to change SIM cards.

My experience with SIM cards is that there is very little stored there (phone number, carrier code, and sometimes contacts).

Richmond

There is NOTHING stored on an iPhone sim card ...........do catch up

Afisher01 wrote:

Hello, I was wondering what would happen to my files on my phone/music/photos etc when I change my sim card please, and if you would be ever so kind as to let me know how to do this properly that would be much appreciated many thanks.

If your iPhone is not carrier locked you can change sim at will (with any compatible iPhone Carrier sim although I always turn iPhone off before doing so )

If locked to a Carrier then you can as @Courcoul has said do the same but only with that Carriers sim

The sim contains NO data on an iPhone so will have no effect on the iPhone and its data

Of course it stores the number and Carrier APN bu nothing else ,thought you would have grasped that

and sometimes contacts).

When did iPhones start storing contacts on the sim

I was told there was very little stored on the sim card, just the carrier code and carrier information, but that your credit card info was also stored on it??? Anyone know for sure?

Just wanted to double check because it was the guy at AT&T that told me that, and he said not many knew about it. Thanks.