What is a carrierlock

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SIM lock:

A SIM lock, network-lock, CARRIER LOCK, imei lock or (master) SUBSIDY lock serves as a technical constraint built into CDMA and GSM mobiles by manufacturers to be used by carriers to limit using these phones to a particular locations and/or networks. This is contrary to a cell phone (retrospectively called SIM-free or unlocked) which doesn't impose any SIM restrictions.SIM locking is incredibly common if subsidized handsets are sold with pre-paid contracts. It is important to note, however, that the technology associated with the phone will need to be compatible with the system being employed by the network carrier. A GSM mobile phone will only function with a GSM carrier and will never operate on a CDMA network. Similarly, a CDMA mobile phone will only work with a CDMA service and won't function on a GSM network. Take note that new (2013 onwards) higher priced cellphones are capable of supporting both CDMA and GSM technologies, allowing for customers to use their smart phones on nearly every network.

Unlocking Technology:

Normally, a locked mobile will display a message if a restricted SIM is used, requesting the unlock code. On modern phone models working on Android mobile phone software, the phone is going to display a message stating “SIM network unlock PIN” or “Enter Network Lock Control Key” if it is network locked. Windows phones will display the message, “This SIM card can only be used on specific networks. Contact your customer service center for the unlock code”. Several other devices may show different messages which include "Enter special code" or "Enter unlocking code," or sometimes the handset may simply present a message stating that it's locked. The minute a valid code is typed in, the mobile will display "Network unlocked” or “Network unlock successful”.


Smartphone suppliers have financial incentives both to bolster SIM lock security (which placates service companies and allows exclusivity discounts) and to weaken it (broadening a phone's overall appeal to users who are usually not interested in the provider that offers it). At the same time, making it too difficult to unlock a mobile may possibly make it considerably less desirable to network service providers with a legal duty to provide unlock codes for certain handsets or in certain countries.

Unlocking Services:

Quite a few companies provide a unlocking service . This service calls for people who would like to unlock a mobile phone handset to supply their IMEI number to a unlocking company and in most cases they will also require the country and network the phone is locked to, frequently sent by email or submitted on their web-site. The company will then provide (for a fee) the unlock code for the mobile phone. For a few manufacturers as in Nokia and Samsung a variety of services additionally offer unique remote-unlocking software with instructions, where a cable connection is needed to remove the SIM lock from home. Such organizations may email the unlocking code or software which can remotely unlock the device. The cost for unlocking a cellphone may fluctuate dependent upon the network its locked to and the device model itself, as every unlock code is unique to each specific device.

Unlocking Service Providers:

Disappointingly there are a lot of fraudulent sites operating in the cell-phone unlocking industry. Consequently it is prudent to ensure you locate a genuine supplier for this service. To assist with your search for a trustworthy company, we've provided a list just below (and in no particular order) of several genuine organisations currently offering such services.

Reputable Mobile Phone IMEI Unlocking Service Providers: