identifierfor

identifierForVendor, commonly referred to as the identifierForVendor (IDFV) for short, is a per-device identifier provided by Apple’s platforms to help apps identify a device to vendors. The value is associated with the vendor of the app suite, not with a single app.

How it works: The identifierForVendor is the same for all apps from the same vendor on a device. It remains stable across app launches, device restarts, and most OS updates, but it changes if the user uninstalls all apps from that vendor and then reinstalls at least one of them. The value can be nil if there are no apps from the vendor installed on the device at the time of access.

Usage: In Swift, you access it via UIDevice.current.identifierForVendor?.uuidString. In Objective-C, [[[UIDevice currentDevice] identifierForVendor] UUIDString]. The result is an NSUUID string. Developers typically use it for basic analytics, debugging, or feature gating within the same vendor’s app ecosystem, while avoiding cross-vendor attribution.

Privacy and limitations: The identifierForVendor is not intended for long-term cross-device or cross-vendor tracking. It is scoped to the vendor and can reset if all apps from that vendor are removed. It is not a guaranteed permanent device ID, and relying on it as a universal device identifier is discouraged. For cross-app or cross-device identity, other mechanisms such as the advertising identifier (IDFA) or user-authenticated approaches should be considered, in compliance with platform policies and user consent.

See also: IDFA, App Tracking Transparency, UIDevice.