Do you need to turn off your phone when changing SIM card?
No, you don’t have to power off.
SIM cards can be removed at any time.
The only thing to do before removing an SD card is to Unmount it (in the Settings>Storage menu).
If you don’t see an option with the word “Unmount,” then look for an Eject icon associated with the SD card..
Should I turn off iPhone before removing SIM card?
Before removing or inserting a SIM card, you must turn off your iPhone. Press and hold the Sleep/Wake button, then slide the Power icon to the right. Note: A SIM card is required in order to use cellular services when connecting to the AT&T network.
What happens if you switch SIM cards in iphones?
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.
Do you have to switch SIM cards when you get a new iPhone?
iPhone SIM cards only store small amounts of customer data, including your phone number and billing information. They do not store contacts, images, apps, and other data, which must be transferred separately when you get a new iPhone.