How can I find my iPhone's unique device identifier (UDID)?
The Unique Device IDentifier or UDID is a 40-character string composed from various hardware identifiers on iOS devices. The UDID will be unique on each device, and can be used along with app-specific user IDs to identify app-specific data on developers' servers. To find your UDID:
1. Connect your iPhone to the computer and open iTunes.
2. Make sure your iPhone is selected in the left menu and click the Summary tab.
3. Click your Serial Number and the UDID will appear. You can copy the UDID onto the clipboard by typing Command + C in Mac OS or Control + C in Windows.
4. Paste your UDID into a text editor or other applications.