# xpc_activity_unregister(_:) Unregisters an activity with the specified identifier. ``` func xpc_activity_unregister(_ identifier: UnsafePointer) ``` ## Parameters `identifier` The identifier of the activity to unregister. ## Discussion A dynamically registered activity will be deleted in response to this call. Statically registered activity (from a launchd property list) will be reverted to its original criteria if any modifications were made. Unregistering an activity has no effect on any outstanding [`xpc_activity_t`](/documentation/XPC/xpc_activity_t) objects or any currently executing [`xpc_activity_handler_t`](/documentation/XPC/xpc_activity_handler_t) blocks; however, no new handler block invocations will be made after it is unregistered. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)