The SIM card is another type of storage medium on your iPhone. It not only maintains contacts but also SIM messages on your iOS smartphone. If you have SIM card issues on your iPhone, withdrawing and re-inserting the SIM card can assist. Here's how to insert and remove the SIM card from your iPhone 8 for iOS beginners.

1. Turn off your iPhone 8. Check that it is totally switched off.
2. Take a paper clip or SIM ejector with you.
3. On the right side of your iPhone, look for the SIM tray.
4. Insert the SIM ejector or pin into the little hole and gently push it out until the SIM tray pops out.
5. Take the SIM card out of the SIM card tray. Examine the SIM card to ensure there are no visible signs of damage.
6. Insert the SIM card into the SIM tray, aligning the notched corner.
7. Replace the SIM card.
8. Turn on your device and start using network services.