What is a IMEI-Lock?
From EjWiki
This is unlike a mobile phone (retrospectively called SIM-free or unlocked) that doesn't enforce any SIM constraints.
Unlocking Technology: Normally, a locked handset will show a message if a restricted SIM is used, requesting the unlock code. On new phone models working on Android mobile phone software, the cellphone will show a message saying “SIM network unlock PIN” or “Enter Network Lock Control Key” if it's network locked. Windows phones are going to show the message, “This SIM card can only be used on specific networks. Contact your customer service center for the unlock code”. Other models may well show different messages for example , "Enter special code" or "Enter unlocking code," or in some circumstances the phone will simply present a message stating that it's locked. Whenever a valid code is typed in, the mobile phone will display "Network unlocked” or “Network unlock successful”.
Economics: Mobile manufacturers have commercial incentives both to enhance SIM lock protection (which placates mobile phone network organisations and allows exclusivity discounts) and also to weaken it (widening a device's overall appeal to users that aren't interested in the service provider that offers it). Furthermore, making it very hard to unlock a phone might make it significantly less desirable to network service providers that have a legal responsibility to provide unlock codes for some handsets or in certain countries.
Unlocking Services: Some organizations offer a online unlocking service. This service requires those people that want to unlock a device to give their IMEI number to a service supplier and quite often they will also request the country and service provider the mobile phone handset is locked to, frequently sent through email or submitted on their web site. The organization then will supply (at a cost to you) a unlock code for the device. For many brands for example Nokia and Samsung many services also offer unique remote-unlocking software with guidance, when a cable is required to remove the SIM lock at home. Such companies may well email the unlocking code or software which will remotely unlock the unit. The cost for unlocking a telephone may change depending on the network it's locked to and the smartphone model itself, as each unlock code is unique to each specific device.
Unlocking Service Providers: Disappointingly there are a lot of fraudulent on line retailers operating in the smart-phone IMEI unlocking industry. As a result it pays to be sure you find a reputable service provider for these services. Take the necessary precautions and investigate all potential dealers in advance of choosing to submitting an order. In the case of online providers, make sure they document their registered business name and corresponding registration information (every genuine organization is required to be legally registered with all the official governing bodies within their country of origin) and make certain they supply a genuine registered address and contact details on their web site. In addition ensure that any payments made are via legitimate sources as in a recognised bank or financial institution using a debt or credit card, but do not ever make payment via a direct transfer as this provides no fiancial safeguards. To assist with the search for a legitimate company, we have supplied a checklist beneath (and in no particular order) of several legitimate organizations currently offering such services.
Reputable Mobile Phone IMEI Unlocking Service Providers:
