How do you reset a Yealink IP Phone to factory default settings?

Method 1: Via web interface.
  1. Login to the web UI of the phone
  2. Go to Settings → Upgrade page, select Reset to Factory Settings
  3. Press OK to continue, press Cancel to quit.
Method 2: Via phone menu.
  1. Press Menu Softkey.
  2. Go to Settings → Advanced UI, enter the password to continue.
    Select Reset to Factory option.
  3. The LCD screen will prompt you with: “Warning, Reset to Factory Setting”.  Press OK to continue.
Method 3: Hard reset on the device

Press and hold the [OK] button for about 15 seconds.

 

Note: Press and hold the [X] button for about 5 seconds to power cycle the device.

Note: The phone can take a few minutes to reset to factory default settings.  Ensure that the device does not lose power during this time, or it may cause damage to the phone’s software.