---
title: Core Telephony
framework: Core Telephony
role: collection
role_heading: Framework
platforms: [iOS 4.0+, iPadOS 4.0+, Mac Catalyst 14.0+, macOS 10.10+]
path: coretelephony
---

# Core Telephony

Access information about a user’s cellular service provider, such as its unique identifier and whether the carrier allows VoIP.

## Overview

Overview Use the Core Telephony framework to obtain information about a user’s home cellular service provider. Carriers can use this information to write apps that provide services only for their own subscribers. You can also use this framework to obtain information about current cellular calls. A CTCarrier object gives you information about the user’s cellular service provider, such as whether it allows use of VoIP (Voice over Internet Protocol) on its network. A CTCall object gives you information about a current call, including a unique identifier and state information such as dialing, incoming, connected, or disconnected. note: VoIP and cellular services through Core Telephony are unavailable for compatible iPad and iPhone apps running in visionOS. You can still use the APIs of this framework, but services don’t return carrier information.

## Topics

### Service information

- [CTTelephonyNetworkInfo](coretelephony/cttelephonynetworkinfo.md)
- [iPhone quick switch](coretelephony/iphone-quick-switch.md)

### eSIM

- [CTCellularPlanProvisioning](coretelephony/ctcellularplanprovisioning.md)
- [CTCellularPlanProvisioningRequest](coretelephony/ctcellularplanprovisioningrequest.md)
- [CTCellularPlanProperties](coretelephony/ctcellularplanproperties.md)
- [CTCellularPlanCapability](coretelephony/ctcellularplancapability.md)

### SIM

- [CTCellularPlanStatus](coretelephony/ctcellularplanstatus.md)

### Subscriber information

- [CTSubscriber](coretelephony/ctsubscriber.md)
- [CTSubscriberDelegate](coretelephony/ctsubscriberdelegate.md)
- [CTSubscriberInfo](coretelephony/ctsubscriberinfo.md)

### Cellular data access

- [CTCellularData](coretelephony/ctcellulardata.md)

### Network slicing

- [CTSlicingManager](coretelephony/ctslicingmanager.md)

### Errors

- [CTError](coretelephony/cterror.md)

### Deprecated

- [CTCarrier](coretelephony/ctcarrier.md)
- [CTCall](coretelephony/ctcall.md)
- [CTCallCenter](coretelephony/ctcallcenter.md)