Your phone's SIM card allows the device to make calls, send texts, and connect to the internet. The SIM card provides a phone number that identifies your device on the carrier's network, whether it's ...

The new Samsung Galaxy Note 5 requires a nano SIM card for you to place calls, access the Internet, download applications, and share photos over your network service ...

Seeing “No SIM” or “Invalid SIM” on iPhone? Check your SIM card, restart, or update your carrier settings. Simple fixes often ...

(Subscriber Identity Module lock) A function in GSM cellphones that restricts the phone's use to a particular cellular carrier identified by a SIM card. SIM locks are used to ensure subscribers finish ...

To check if your Android phone is unlocked, try swapping in another SIM card or test your network settings. If calls work, ...