AASTRA 4420 IP Basic (SIP) for MX-ONE User Guide - Manual (Page 27)

27 Dialog 4420 IP Basic
During Calls
Transfer
You have an ongoing call and you want to transfer the call to
another extension. Ô
Line/Hold Press.
Wait for dial tone. z
Call the third party.
Ô
Transfer Press
or
press before or after answer.
The ongoing call is transferred.
Note: If you have put more than one call on hold, the last
call that was put on hold will be transferred. If the dialed
extension is busy or Transfer is not allowed, your phone will
ring again.