The IMEI is a 15 to 17 digit number unique to your phone which you can obtain by typing *#06#
Simply type the first 15 numbers into the request form, ignoring all other characters such as letters, dashes, hyphens etc.
If your IMEI is longer than 15 digits, input the first 15 digits only.
CAUTION! Make sure you enter the IMEI as displayed on your phone and not on the box or packaging.