Press Menu, and select Settings and Security settings. Select

• PIN code request to set the phone to ask for your PIN code every time the phone is switched on. Some SIM cards do not allow the PIN code request to be turned off.
• Call barring service (network service) to restrict incoming calls to and outgoing calls from your phone. A barring password is required.
• Fixed dialling to restrict your outgoing calls to selected phone numbers if this function is supported by your SIM card. The PIN2 code is required.
• Closed user group is a network service that specifies the group of people whom you can call and who can call you. For more information contact your network operator or service provider.
• Security level. Select Phone and the phone will ask for the security code whenever a new SIM card is inserted into the phone. Select Memory and the phone will ask for the security code when the SIM card's memory is selected and you want to change the memory in use or copy from one memory to another.
• Access codes to change the security code, PIN code, PIN2 code or barring password. Codes can only include numbers from 0 to 9.