How to check if your iPhone is unlocked so you can change your wireless carrier

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

How to change your Wi-Fi network in the Control Center on an iPhone with iOS 13

It's easy to change your Wi-Fi network directly in Control Center on an iPhone with iOS 13 — without having to use Settings.
BGR

How To Tell If An iPhone Is Carrier-Locked

What does it mean if your iPhone is locked? If your iPhone is carrier-locked, it's only going to work with the cellular provider that locked it. However, if your iPhone isn't locked, you'll be able to ...
Pensacola News Journal

Is there an AT&T outage? How to check if your phone is in SOS mode

If you look down at your phone and notice that it’s in SOS-only mode, there is a good chance that it’s not your fault. AT&T currently has roughly 4,600 user reports of outages across the United States ...