EID
The EID is a 32-digit number that is unique to your Apple Watch. Every EID on every Apple Watch is different.
You will need this number to book a mobile/cellular plan for your smartwatch.
The EID number can be found in one of the following ways:
Option 1 (recommended):
Open the Watch app on your iPhone
Select your paired Apple Watch
Then select General > About
Scroll down to find your EID
Long-press on the number to copy it
Option 2:
The EID is also printed on the back of the box your Apple Watch was packaged in.
*Note: using this method means you must manually enter 32 digits without error during checkout.
Option 3:
Locating your EID number via your Apple Watch
On your Apple Watch, select Settings > General > About > EID
Scroll down to find your EID
*Note: You can view your EID number here, but you cannot purchase a mobile plan via your Apple Watch. You can only book plans via iPhone or desktop.
Once you have located your EID number, you can then copy and paste it into the checkout process when prompted.