An ID number that is globally unique for each new CDMA mobile phone in the world. It identifies that phone to the network, and can be used to flag stolen or lost phones.
MEID is a replacement for ESN (electronic serial number). MEID began replacing ESN in 2005.
ESN numbers are 32-bit, while MEID numbers are 56-bit.
A 32-bit ESN means there are only 4 billion unique ESN numbers. Combined with other constraints, enough CDMA phones were produced by the end of 2005 that the industry started to run out of unique ESNs.
With 56 bits, MEID provides for over 16 million times as many unique numbers as with the ESN system, ensuring the world will not run out of numbers again.
However, MEID support must be added to all new CDMA phones, and all CDMA networks must be upgraded to support MEID.
MEID is equivalant to IMEI for GSM and WCDMA phones. MEID is also designed to be compatible with IMEI for phones that include both CDMA and GSM/WCDMA technology.