iPhone 7 data not working after carrier transfer

While iPhone settings allow you to view and manage certain aspects of your cellular plan, such as enabling or disabling data roaming, selecting a preferred network, and monitoring usage, adding a new data plan or modifying an existing one (e.g., upgrading, downgrading, or switching to a different plan) must be done through your service provider. This is because the carrier controls plan availability, pricing, and account changes. Some carriers allow plan modifications through their app or website, but direct changes cannot be made from the iPhone’s settings alone.