What is a SIMLock

From Security Holes
Jump to: navigation, search
SIM lock:

A simlock, NETWORK-LOCK, Carrier-Lock, IMEI-Lock or (Master) subsidy lock is really a technical constraint built into GSM and CDMA cell phones by manufacturers to be used by carriers to limit the usage of these phones to particular countries and/or networks. This is as opposed to a mobile phone (retrospectively called SIM-free or unlocked) which doesn't impose any SIM limitations.SIM locking is incredibly common if subsidized handsets are offered with pre pay contracts. It is essential to note, however, that this technology accompanying with the phone will need to be compatible with the system used by the network carrier. A GSM cellphone can only function with a GSM carrier and will never operate on a CDMA service. Equally, a CDMA mobile phone can only work with a CDMA service and will never work on a GSM service. Keep in mind that modern (2013 onwards) higher priced mobile phones are equipped to support both CDMA and GSM technologies, allowing for users to utilize their smartphones on any type of network.

Unlocking Technology:

Frequently, a locked mobile will display a message if a restricted SIM is used, asking for the unlock code. On the latest phone models operating on Google android software, the cell phone will show a message stating “SIM network unlock PIN” or “Enter Network Lock Control Key” if it's network locked. Windows phones should show the message, “This SIM card can only be used on specific networks. Contact your customer service center for the unlock code”. Some other handsets may very well show a variety of messages for example "Enter special code" or "Enter unlocking code," or in some instances the device may simply show a message saying it's locked. When a valid code is entered, the mobile will display "Network unlocked” or “Network unlock successful”.


The main reason to unlock a mobile is to be able to use it with a different SIM card. Customers might like to continue using their smartphone but with a new provider or when traveling overseas they might need to connect to a international network with a pre-paid subscription.

Unlocking Services:

cellphone IMEI unlock codes
A number of businesses offer a online smartphone unlocking service . This service requires those people who wish to unlock a mobile phone to give their IMEI number to a service supplier and quite often they will also need the country and network the mobile phone is locked to, frequently sent by email or submitted on their web site. The company then will provide (once you have paid) a unlock code for the handset. For many manufacturers as in Nokia and Samsung a variety of services also provide special remote-unlocking software with directions, where a cable connection is needed to remove the SIM lock at home. Such organizations may well email the unlocking code or software which will remotely unlock the device. The price for unlocking a cellular phone will change depending on the network it is locked to and the smartphone model itself, as each unlock code is unique to each unique device.

Unlocking Service Providers:

Disappointingly there are a massive number of fraudulent organizations operating in the cell phone network unlocking industry. As a result it is recommended to be sure you find a reliable supplier for this service. Take the necessary precautions and investigate all prospective dealers in advance of choosing to making an order. In the case of online providers, make sure they list their public organization name and matching registration details (every legit organization is required to be legally registered with all the official authorities for their country of origin) and ensure they provide a genuine registered address and contact details on their web site. Furthermore make certain that any payments made are thru legitimate methods as in a recognized bank or financial institution using a debt or credit card, but do not ever make payment via a direct transfer because this provides no fiancial security. To assist with the search for a reputable company, we've supplied a list below (and in no particular order) of several genuine organizations currently offering such services.

Reputable Mobile Phone IMEI Unlocking Service Providers: