The Adjust Mobile Measurement Glossary
What is the Identifier for Vendor (IDFV)?
The definition of IDFV?
The Identifier for Vendors (IDFV) is a code assigned to all apps by one developer and is shared across all apps by that developer on your device. The value of the IDFV is the same for apps from the same developer running on the same device. A different value is returned for apps on the same device that come from different developers and for apps on different devices, regardless of the developer.
Why is the Identifier for Vendor (IDFV) important?
IDFVs are important as they provide a means to run cross-promotional iOS campaigns which include ‘limit ad tracking’ (or LAT) users — without relying on fingerprinting. So long as an IDFV is passed in the tracker URLs, the IDFV can provide marketers with more accurate attribution data for iOS campaigns.
What is the difference between the Identifier for Vendor (IDFV) and the Identifier for Advertiser (IDFA)?
The Identifier for Advertisers (IDFA) is a random device identifier assigned by Apple to a user’s device. Advertisers use this to track data so they can deliver customized advertising. The IDFA is used for tracking and identifying a user (without revealing personal information).
The IDFA is assigned at the device level and can be reset by users. This differs from the IDFV which is assigned to all apps by the one vendor and does not persist once all apps from that vendor are uninstalled. The Android equivalent of the IDFA is called GPS-ADID (or Google Play Services ID for Android). A user has access to their GPS-ADID in the settings menu under "Google - Ads". They can also reset the ID and disable ad personalization. To learn more about these terms, take a look at our introduction to app tracking.
Can you reset an IDFV?
Typically, the IDFV is determined based on data provided by the App Store about the developer. If the app was not installed from the App Store (for example, enterprise applications and apps in development), a provider ID is calculated based on the app's bundle ID.
The value in this property remains the same while the app (or another app from the same vendor) is installed on the iOS device. The value changes if the user deletes all apps from that vendor from the device and then reinstalls one or more of them.