The IMEI database maintains 3 different coloured list. Each has a specific use that benefits operators and industry affiliates.
As devices have become more sophisticated and more expensive, they are also more attractive to thieves. Recent years have seen an increased need for the IMEI DB to be used as a tool to combat handset theft by ensuring the identities of stolen devices can be shared across networks around the world. The IMEI DB supports what is known as a “black list”. The black list is a list of IMEIs that are associated with mobile devices that should be denied service on mobile networks because they have been reported as lost, stolen, faulty or otherwise unsuitable for use. This list is stored in the Central Equipment Identity Register (CEIR) which acts as a central system for network operators to share their individual lists so that devices denied service (blacklisted) by one network will not work on other networks.
The engagement of governments and law enforcement agencies with the network operator community is a powerful way to deter handset theft. In markets where handset theft is perceived to be a problem, the GSMA strongly encourages use of the IMEI DB as a platform to exchange stolen handset data with law enforcement and other operators. Use of the IMEI DB for blacklist exchange is free of charge to member operators and government authorities.
Mobile phone users whose devices have been stolen should note that GSMA does not add device IMEIs to the IMEI DB blacklist or otherwise assist with incidents of device theft. Device theft should be reported to the subscribers service provider and to the police. For more advice on how to reduce the chances of your device being stolen, and what to do if your device is stolen, click here.
The White List is composed of all TAC that are permitted for use on networks. Note that the white list does not contain the individual IMEIs of the TAC range. The information contained in the TAC includes the manufacturer, model, equipment type, radio bands and interfaces of the device model.
This information helps Mobile Network Operators identify devices requesting network access and determine if the device is allowed. It is also helpful for knowing what services to offer to the device subscriber and if the device is due for an “over-the-air” software update.
Besides the Black and White Lists, Mobile Network Operators have the possibility to use a grey list. The Grey List, like the Black List, contains actual IMEIs. Devices on the Grey List are tracked by the network for evaluation or other purposes but are not barred from service. If the device is eventually determined to be faulty or troublesome, the Operator may contact the device owner to advise appropriate action.
If the device continues to cause problems for the Operator, it may be entered into the Black List.