What is a master SUBSIDY lock

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SIM lock:

A SIM-LOCK, network lock, CARRIER-LOCK, IMEI-Lock or (Master) subsidy lock is actually a technical limit built into CDMA and GSM cell phones by producers to be used by carriers to restrict the usage of these phones to a particular locations and/or networks. This is in comparison with a mobile phone (retrospectively called SIM-free or unlocked) that doesn't impose any SIM restrictions.

The majority of cell phones can be unlocked to operate with any GSM network provider, although the phone may still display the original branding and may not support popular features of the new carrier. Besides the locking, mobile phones might also have firmware that come with them which is specific to the network provider. This firmware is installed through the service provider which is separate from the locking mechanism. Virtually all mobile phones can be unbranded by re-flashing a different firmware variation, a procedure suitable for advanced users only.

Unlocking Technology:

A mobile can be unlocked simply by entering a code supplied by the network operator. Alternative mechanisms contain software operating on the device or a computer attached to the handset, hardware devices that link to the phone or over-the-air by the service provider. Almost always the unlock operation is permanent. The code needed to get rid of all locks from a smartphone is referred to as the master code, network code key, or multi-lock code. Generally if the handset is carrier locked it will typically show one of these messages: SIM network PIN blocked, Enter lock PIN.


Handset suppliers have commercial incentives both to enhance SIM lock protection (which placates service providers and will allow exclusivity deals) and then to weaken it (broadening a smartphone's overall appeal to consumers that may not be interested in the service provider that offers it). At the same time, making it too hard to unlock a smartphone may possibly make it much less attractive to mobile phone network service providers who have a legal liability to provide unlock codes for certain devices or in certain countries.

Unlocking Services:

Several organizations provide a carrier cell phone unlocking service . This service calls for people that wish to unlock a phone to supply their IMEI number to a unlocking company and often they will also ask for the country and service provider the mobile phone handset is locked to, sometimes sent via email or entered on their web site. The supplier will then provide (at a cost to you) the unlock code for the device.

Unlocking Service Providers:

Regrettably there are a lot of dodgy on line retailers working in the mobile phone carrier unlocking industry. Consequently it pays off to be certain you find a reliable supplier for such a service. To aid with your search for a legitimate supplier, we have provided a listing just below (and in no specific order) of several legit organisations currently offering such services.

Reputable Mobile Phone IMEI Unlocking Service Providers: