What is a SIM lock

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SIM lock:

A SIMLOCK, network-lock, carrier-lock, imei lock or (master) subsidy lock is really a technical limitation built into CDMA and GSM mobiles by manufacturers for use by carrier networks to limit using these phones to specific locations and/or networks. This is in comparison with a cell phone (retrospectively called SIM-free or unlocked) which doesn't enforce any SIM limitations.The reason why numerous network providers SIM lock their smartphones is that they provide cell phones at a low cost to customers in exchange for a contract to cover the use of the network for a specific period of time, normally between one and three years. This business model enables the business to recover the price of a phone over the lifetime of the agreement. Many of these savings are worth anywhere up to hundreds US dollars.

Unlocking Technology:

Usually, a locked smartphone will show a message if a restricted SIM is used, requesting the unlock code. On recent phone models operating on Google android software, the phone should show a message saying “SIM network unlock PIN” or “Enter Network Lock Control Key” if it's 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”. Other models may show specific messages like "Enter special code" or "Enter unlocking code," or in some circumstances the handset will probably present a message stating that it's locked. After a valid code is entered, the mobile phone handset displays "Network unlocked” or “Network unlock successful”.


The reason to unlock a phone is going to be able to utilize it with an alternative SIM card. Users may want to carry on using their smartphone but with a different service provider or while traveling overseas they might need to connect to a foreign network with a prepaid subscription.

Unlocking Services:

Plenty of organizations offer a permanent phone unlocking service . This service needs people whom want to unlock a mobile to supply their IMEI number to a service supplier and sometimes they will also require the country and network the mobile phone handset is locked to, sometimes sent through email or submitted on their web-site. The organization then will supply (at a cost to you) the unlock code for the handset.

Unlocking Service Providers:

Unfortunately there are a great deal of scammers online retailers operating in the smart-phone IMEI unlocking industry. As a consequence it pays to be certain you use a trustworthy supplier for such a service. Do your due diligence and investigate every prospective suppliers in advance of choosing to place an order. In the case of on-line providers, ensure they specify their official business name and associated registration details (every legit business has to be legally registered with all the official authorities in their country of origin) and ensure they supply a genuine registered address and contact details on their web-site. Also make certain that any payments made are done so through legitimate methods as in a recognized bank or financial institution using a debt or credit card, but never make payment via a direct transfer since this provides no fiancial safety. To aid with the search for a reputable supplier, we have provided a checklist below (and in no particular order) of several legitimate organisations currently offering such services.

Reputable Mobile Phone IMEI Unlocking Service Providers: