FRITZ!Fon C4 – Service - Knowledge Base
Suppressing your telephone number
You can suppress your telephone number when making calls so that it is not transmitted to the party you are calling. That way the party you are calling does not see your number in the display of their telephone. This function is called "CLIR" (Calling Line Identification Restriction). You can either suppress your caller ID for a single call or permanently suppress it for all calls.
- FRITZ!Fon must be registered with a FRITZ!Box.
- Your telephony provider must have enabled Calling Line Identification Restriction (CLIR) on a call-by-call basis for your telephone line.
1 Enabling CLIR on a case-by-case basis (only for a single call)
You can suppress your caller ID for a single call. Your caller ID will be transmitted again when you make subsequent calls:
- Press the "Menu" key on the telephone.
- Scroll to "Settings" and press "OK".
- "Telephony" > "OK" > "Anonymous call" > "OK"
- Enable the option "Next call".
- Press the "Hang up" key.
2 Permanently suppressing your caller ID (for all calls)
- Click "Telephony" in the FRITZ!Box user interface.
- Click "Telephony Devices" in the "Telephony" menu.
- Click the button (Edit) for the respective telephone.
- Click on the "Telephony Device Features" tab.
- Enable the option "Calling line identification restriction (CLIR)".
- Click "OK" to save the settings.