Ericsson Premium - Security; Block Extension

Security
BusinessPhone – Premium Telephone48
Security
You can block your extension in order to prevent unauthorized use
of your telephone, e.g. if your external calls are placed on a specific
account number.
Block extension
u Lift the handset
*72# Dial to block your extension
Verification tone.
Un-block extension
u Lift the handset
#72* Dial
z Dial your password
# Press to re-open
Verification tone. Your extension is open for use.