You can check to see if your iPhone is unlocked from a carrier using any of a few different methods.

eSIM is the latest sim card technology that allows you to access mobile networks without needing to get a physical sim card. Certain new phones such as Apple’s iPhone, offer the eSIM feature along ...

If you need to find out your iPhone's carrier without a SIM card installed, you can do so through the Settings app.

Apple continues to phase out the physical SIM card tray on iPhones, with the latest models relying solely on eSIM technology in more countries.