A the numeric code ( password ) that prevents user access to configuration characteristics of the particular phone . Especially for this design is that of reprogramming the phone by another user, prevent . This feature usually is the phone " locked " can be interpreted . Phone, " not locked " also exist that are able to work with another user, re-planning . The reason for this system, being sold phone returns . phone prices below are sold ( to the detriment of the user ), with the impression that the price difference in the cost of services monthly compensation . Loss of deposit, that the next compensation to be subsidized . For the benefit of the Financial Operator, etc., the user should be the phone to buy, and later with another operator . MSL almost this impossible . Phone lock is not usually much more expensive than the phone locked because they are no to offset the cost does not exist.