The error message "Cellular Plans From This Carrier Cannot be Added" typically appears on a mobile device when attempting to add a new cellular plan from a carrier that is not supported by the device. This message can occur for several reasons, including:
Incompatible device: Some carriers only support certain types of devices. If your device is not compatible with the carrier's network, you may receive this error message.
Device locked to a carrier: Some mobile devices are locked to a specific carrier, meaning they can only be used with that carrier's network. If your device is locked to a different carrier than the one you are attempting to add a plan from, you may receive this error message.
Carrier restrictions: Some carriers may have restrictions on the types of plans that can be added to a device. For example, they may only allow postpaid plans and not prepaid plans.
If you are receiving this error message, you should contact your carrier's customer support for assistance. They may be able to provide additional information about why the error is occurring and what steps you can take to resolve it.