MSL
(Master Subsidy Lock)
A numeric code (password) that prevents a user from accessing certain technical settings of a phone. It is specifically designed to prevent a phone from being reprogrammed to work with a different carrier (service provider).
MSL is relevant only to certain types of phones, such as CDMA phones. Other types of phones may have a similar type of code that goes by a different name.
This is what is usually meant when a phone is referred to as "locked". There are also "unlocked" phones that can be reprogrammed to work with a different carrier.
The reason for this system is the way phones are often sold. Many phones are sold below cost, (at a loss to the carrier,) with the expectation that the money will be recouped in the cost of the monthly service plan. The up-front loss that is later recouped is called a Subsidy.
For this to work financially for the carrier, the user must not buy the phone and then use it with a different carrier. The MSL makes that nearly impossible.
Unlocked phones are ususally much more expensive than locked phones, because there is no subsidy to offset the cost.
Last updated Jan 3, 2014 by Rich Brome
Editor in Chief Rich became fascinated with cell phones in 1999, creating mobile web sites for phones with tiny black-and-white displays and obsessing over new phone models. Realizing a need for better info about phones, he started Phone Scoop in 2001, and has been helming the site ever since. Rich has spent two decades researching and covering every detail of the phone industry, traveling the world to tour factories, interview CEOs, and get every last spec and photo Phone Scoop readers have come to expect. As an industry veteran, Rich is a respected voice on phone technology of the past, present, and future.
