With a desktop (and an iPhone charge cable):
- Connect your iPhone to your computer
- Open iTunes and go to the phone section at the top left of the software
- Your phone serial number will show up, click on it and you'll get your UDID
- Right click and copy the UDID
Without a desktop (without an iPhone charge cable):
- Go to https://betafamily.com/superudid
- Enter your e-mail to receive an iOS register link
- Once you receive the link, click on it and install a profile to install on your phone.
- Follow the steps and enter your Account Manager's email in the "Developer's email".
- You're done!
UDID means Unique Device Identifier and contains 40 characters.
Here is an example: f1atr006f4982083863bc7e1be2cbd149509d0ce