Mobile phones can be used in countries with different emergency numbers. A traveller visiting a foreign country does not have to know the local emergency numbers, however. The mobile phone and the SIM card have a preprogrammed list of emergency numbers. When the user tries to set up a call using an emergency number known by a GSM or 3G phone, the special emergency call setup takes place. The actual number is not even transmitted into the network, but the network redirects the emergency call to the local emergency desk. Most GSM mobile phones can dial emergency calls even when the phone keyboard is locked, the phone is without a SIM card, or an emergency number is entered instead of the PIN.
Most GSM mobile phones have 112, 999 and 911 as pre-programmed emergency numbers that are always available.[1] The SIM card issued by the operator can contain additional country-specific emergency numbers that can be used even when roaming abroad. The GSM network can also update the list of well-known emergency numbers when the phone registers to it.
