Netlock means network lock. Netlock is a function with which mobile phones can be blocked for certain mobile phone networks
. The corresponding mobile phone can only be operated in the approved mobile networks. The Netlock function is implemented when the mobile phone is manufactured and is comparable to SIMlock, but Netlock can be used to restrict services
and exclude countries. Netlock is therefore tied to the SIM card provider or the network operator. Changing the SIM card does not mean that the user can make calls on a different mobile network. Since different network operators support several networks, the restrictions are often not serious. Netlock is bound to the contract period and can be unlocked afterwards free of charge or for a fee. When unlocking, the mobile phone user receives an unlock code from the network operator.