You can lock your handset to prevent external dialling and programming, thereby preventing unauthorised use in your absence, for example.  

Prerequisite: You have defined a personal code or use the default code "00000". 

Locking the handset

Press the Talk key. 

Call the system menu. 

Select and confirm the menu item. 

Enter the PIN code (5 digits, default "00000"). 

Press the On-hook key to end the process.
 

Note:  Even though it is locked, you can still use your handset to answer external calls and make internal calls. When an external connection is established, the following message appears on the display "Telephone Lock Active".  Your handset can also be locked from a central station ().

Unlocking the handset

Press the Talk key. 

Call the system menu. 

Select and confirm the menu item. 

Enter the PIN code (5 digits, default "00000"). 

Press the On-hook key to end the process.