To determine if your Android device is unlocked from a carrier, follow these steps:
- Go to Settings
- Tap on Connections or Network & Internet
- Tap on Mobile Network
- Tap on Network Operators
If the search only returns one result or if you cannot find the option to Search Networks in the network menu, then your phone is locked to a specific carrier.
If your phone displays multiple available networks, it means it is unlocked.
Please note that the names of the settings might vary slightly on different Android devices.