Registering an Additional A400 Handset
- Press and hold the soft key under Menu (The soft keys are under the Caller ID screen and have white lines in them that look like minus signs)
- You will see Press & Hold Base Page Key appear on the screen
- Let go of the soft key
- Press and hold the Page key on the base for about 20 seconds. You should hear a beep and the handset should show HS-2 - HS-5 depending on which handset it is in the order.