The SIM card (Subscriber Identity Module) stores all the essential information about your iPhone. If you plan to switch to a different mobile device while preserving your current data, you can remove the SIM card from your iPhone and insert it into another phone. This can be done using a special SIM removal tool, or sometimes just a paperclip. However, the process can vary slightly depending on the iPhone model.
Steps
Removing the SIM from iPhone 4, 4S, 5, 6, and 6 Plus

Use the correct SIM card. The iPhone 4 and 4S use a Micro SIM, while the iPhone 5 and 6 require a Nano SIM.

Locate the SIM card slot. The SIM card slot is located at the top-right side of the phone.

Use a straightened paperclip or a SIM removal tool. Insert one end of the paperclip into the small hole next to the SIM card slot. Gently push to eject the tray. Remove the SIM card from the tray. Don’t forget to return the tray to its place if you're preparing your phone for warranty service.
Removing the SIM from the first iPhone and iPhone 3G/S

Use the correct SIM card. The iPhone and iPhone 3G/S use a standard-sized SIM card.

Locate the SIM card slot. The first-generation iPhone and iPhone 3G/S have their SIM card slot at the top of the device, right next to the power button.

Use a straightened paperclip or a SIM removal tool. Insert one end of the paperclip into the small hole next to the SIM card slot. Remove the SIM card from the tray. Be sure to replace the tray if you plan to send your device for warranty service.
Removing the SIM from iPad 2, 3, 4, and Mini

Use the correct SIM card. Only iPads that support both cellular and Wi-Fi networks have a SIM card. Standard-sized iPads use a Micro SIM, while iPad Mini uses a Nano SIM.

Locate the SIM card slot. iPad 2/3/4 and Mini have the SIM card slot at the bottom-left. The slot is often hidden inside, but you can easily locate it by turning the back of the iPad toward you.

Use a straightened paperclip or a SIM removal tool. Insert one end of the paperclip into the small hole next to the SIM card slot at a 45° angle. Remove the SIM card from the tray. Ensure you replace the tray if you are sending your device for warranty service.
Removing the SIM from the first iPad

Use the correct SIM card. Only iPads that support both Wi-Fi and cellular networks have a SIM card. The first iPad uses a Micro SIM card.

Locate the SIM card slot. The SIM card slot of the first iPad is located at the bottom-left.

Use a straightened paperclip or a SIM removal tool. Insert one end of the paperclip into the small hole next to the SIM card slot. Remove the SIM card from the tray. Make sure to place the tray back if preparing your device for warranty service.
