---
title: "dataServiceIdentifierDidChange(_:)"
framework: coretelephony
role: symbol
role_heading: Instance Method
path: "coretelephony/cttelephonynetworkinfodelegate/dataserviceidentifierdidchange(_:)"
---

# dataServiceIdentifierDidChange(_:)

Informs the delegate when the identifier changes for the service that’s currently providing data.

## Declaration

```swift
optional func dataServiceIdentifierDidChange(_ identifier: String)
```

## Parameters

- `identifier`: The identifier of the service that’s currently providing data. Use this identifier as the key in doc://com.apple.coretelephony/documentation/CoreTelephony/CTTelephonyNetworkInfo/serviceCurrentRadioAccessTechnology to get the value of the new radio access technology for the service.