Thanks for the response. I'm still searching for some answers. If I do find anything I'll post back on here. Cheers.
I have a solution -
You must enable remote access on Handset 1
From idle screen - press MENU
Answerphone will show - press SELECT
Scroll down to SETTINGS - press SELECT
Scroll down to Remote Access - Press SELECT
Screen will show On/Off - Press SELECT
Scroll Left/Right to select preference - then press SAVE
The process for accessing answerphone from another phone(remote access).
Wait for answerphone to answer.
Wait for answerphone to request access PIN
Answerphone will announce options etc....
here is a link to the full instruction manual. The remote access is very simple to set up using the instructions
Hope it helps