UDID for app testing and provisioning
If someone is preparing an iOS app build for you to test, they may ask for your iPhone or iPad UDID. Sending the right identifier helps them register the exact device that will run the build.
Why testers are asked for UDIDs
Some app distribution methods require devices to be registered before an app can be installed. The UDID tells the developer which device should be included in the provisioning setup.
How to avoid sending the wrong value
Do not substitute your serial number, model name, phone number, or Apple ID unless the developer specifically asks for those. Use a UDID finder and copy the UDID exactly as shown.
What else you may need to share
Developers sometimes also ask for iOS version and device model. UDID Tools displays those details alongside the UDID, so you can copy the exact information needed for troubleshooting.
Need the identifier?
Get your UDID in Safari
Open this page on the iPhone or iPad you want to identify and use the profile flow to copy the result.
Common questions
Is UDID needed for TestFlight?
TestFlight usually uses Apple IDs and invitations. UDIDs are more common for ad hoc builds or other private testing workflows.
Can I use the same UDID for my iPad and iPhone?
No. Each physical device has its own identifier. Run the flow on the exact device that needs to be registered.