User:ViperSnake151/SIM lock

A SIM lock, simlock, network lock or subsidy lock is a capability built into GSM phones by mobile phone manufacturers to allow the phone to only accept specific types of SIM cards. The most common use of SIM locks is to restrict phones provided by one, to only be able to be used with SIM cards supplied by a specific service provider, thus only allowing it to be used on their own network.

The legality of SIM locking varies by countries, some countries do not allow cellphones to be sold locked to a specific service provider, and some countries can require that a service provider be able to offer the "unlocking" of a phone (whether immediately or after a specific time period, and sometimes for a fee). These legalities also took center-stage during the international launches of the iPhone, which is exclusively available only from AT&T in the United States (using a SIM lock to enforce this exclusivity), and the possibility of unlocked iPhones becoming easier to acquire. Some SIM locking mechanisms can also be removed using software hacks.

Germany
The country of Germany does not have any specific law requiring phones be sold without SIM locks. However, T-Mobile was placed under a preliminary injunction requested competing operator Vodafone, who complained that the exclusivity for the iPhone was anti-competitive, which for a short time required T-Mobile to be able to sell iPhones unlocked and without a contract. On December 4, 2007, a German court overturned the temporary injunction, allowing T-Mobile to sell the iPhone with a SIM lock. In addition, T-Mobile will voluntarily offer to unlock customers' iPhone after the contract expires.