I upgraded from an iPhone 5 to XS. the 5 had a mobile-carrier company sim card (non-apple). To save phonecalls, I just plugged in the old sim card into new phone and it worked. I think the new phone has a apple sim card. The sim card that came with the new phone looks newer and more shiny. Are there any disadvantages of sticking with the old sim card? Everything seems like it works. I was just wondering because many but one android user sent me an text message and it didn't go through. The 5 underwent submersion but the water damage detector didn't register water damage.
IPhone – Disadvantages of using sim card from old iPhone
iphonesim
Related Solutions
This is, unfortunately, expected behavior. Whenever you activate an iPhone (which you do as part of an OS install) it talks to Apple's servers and does various things like exchange crypto certs for APNS, etc. It also checks the IMEI of the phone to see what carrier Apple sold it to, and validates the SIM is valid for that carrier (if you buy an unlocked iPhone in a country where you can buy either locked or unlocked phones the vendor will actually copy down the IMEI number of a normal locked phone, and then enter in their system where it gets pushed to Apple's servers as an unlocked phone, there is no physical or configuration difference on the phones).
The easiest way to get it activated is (as you surmised) to use an AT&T SIM. You mentioned you have an iPhone 4, you can activate it with that SIM. There are plenty of companies that sell microSIM to SIM adapters, but if you want to do it right now you can just place the micro SIM directly in the iPhones 3GS's SIM try with tape. I would not recommend doing this on a device you intend to keep the SIM in for a an extended period because the SIM is likely to come loose (and jam the SIM tray), but if you are just inserting it, activating it, and removing it you should be fine so long as you are pretty careful with how you apply the tape and not shaking the phone too much.
I solved the problem by making an appointment at the Genius Bar at the local Apple Store, explaining what I was trying to do, and asking for their help. Even though I purchased a used iPhone 5c from a third-party, they brought out a working new Sprint SIM card and activated the iPhone with Apple (for use as an iPod touch only. with no phone service) for me. They also let me keep the SIM card in case I need it to reset the iPhone.
The new SIM card that the Sprint Store had given me earlier, for one reason or another, did not work.
The Genius in the Apple Store told me that Sprint SIM cards are very specific, and some would work in a 5c and others would not.
The Sprint SIM card model that did work with my iPhone 5C was Sprint part number SIMGLW406C.
The Sprint SIM card model that did not work with my iPhone 5C was Sprint part number SIMGLW406R.
Best Answer
In terms of using the phone day to day, there's no disadvantages with re-using the SIM card from the old phone.
The disadvantage lies primarily with the fact that if you had requested a new SIM card from your provider, you would have received one that could be running newer software (inside the SIM card). This could be relevant if you were the target of a specific hacking attempt, as the SIM card software is rarely, if at all, updated by providers after it is sent out.