To do a proper factory reset of a Panasonic SIP phone you need to have the phone in front of you.
There is a reset option in the web interface but this will only reset any settings that had been set in the web interface itself. Any settings that have been provisioned will persist.
On the phone:
- Press the “setting” button to go into the settings menu
- Dial: #136 on the keypad
- A hidden menu will appear, select “Factory Reset”
- Press up or down to choose “yes” and then Enter
- Repeat the previous step for the “are you sure” prompt
- The phone will now reboot itself
Once rebooted, it’ll be fully reset. Just be aware, if the phone has been provisioned it may well call home to the provisioning server and get some settings applied from that. You’ll have to speak to whoever does your provisioning for us (hopefully us!).