How to Find Your iPhone UDID (With or Without a Mac)

A UDID (unique device identifier) is the ID Apple uses to register an iPhone or iPad for testing. Developers need it before an ad hoc build will install on your device.

iPhones from the XS onward have a 25-character UDID with one hyphen, like 00008110-001A2B3C4D5E6F7A. Older models use 40 hexadecimal characters.

Why Settings doesn't show it

The Settings app shows your serial number and model, but not the UDID. Apps from the App Store can't read it either. That's why every method below goes through Safari or a computer.

1. On the iPhone, with Safari

This is the easiest way for testers, and it needs no computer.

1. Open a UDID link from the developer in Safari. With BuildFerry, this is the app's share link.
2. Tap Allow to download the profile.
3. Open Settings, tap Profile Downloaded, then Install.
4. The profile sends the UDID back to the page and removes itself.

Only use a link from someone you trust. A legitimate UDID profile only asks for device attributes, and BuildFerry's profile shows as Verified because it's signed with a real certificate.

2. On a Mac, with Finder

1. Connect the iPhone with a cable and tap Trust if asked.
2. Select the iPhone in the Finder sidebar.
3. Click the grey line of text under the iPhone's name until it shows the UDID.
4. Copy it and send it to your developer.

3. With Xcode

1. Connect the iPhone.
2. Open Window, then Devices and Simulators.
3. Select the device and copy the Identifier.

4. On Windows, with iTunes

1. Connect the iPhone and open iTunes or the Apple Devices app.
2. Open the device summary.
3. Click the serial number until it changes to the UDID, then copy it.

Skip the UDID step entirely

Sending UDIDs back and forth is the slowest part of ad hoc testing. With BuildFerry the tester opens one link, the UDID is collected by the profile, and once you approve, the iPhone is registered and the build signed. No copying, no spreadsheet.