What is the UDID?
There are many reasons you may need to look up your UDID, IMEI, or serial number of your iOS device. While earlier generations had the serial printed on the back casing of the device, many newer models don't.
Use this guide to locate the UDID for your device.
Obtaining the UDID
- Open iTunes on a PC or MAC computer.
- Connect the iPad to the computer.
- After the iPad is connected, a summary screen will appear.
If the summary screen does not appear, then you may need to click on the device iPad icon 
.
4. Click on the iPad serial text, and the UDID will be displayed.
5. At the top of the iTunes screen, click Edit and then Copy. This will paste your UDID number to the clipboard. From there you can easily copy it into an e-mail or text document.
You can also highlight the UDID, right-click, and select the Copy option from the context menu.