AT&T E560-2 - Manual (Page 8)

Adding new handsets
4
HANDSET 2
Before using a new E560-2/E560-5 handset, you
must register it with the E5640/E5643B/E5655
telephone base. During registration, you must
enter the 15-digit ID number of the telephone
base. The base ID of the E5640/E5643B is
located on the bottom of the telephone base.
For the E5655, you can find the base ID code
in the E5655 base menu. Press
SELECT/MENU
just below the screen on the telephone base,
then press ^
CID
twice and the screen shows
>DISPLAY BASE ID. Press
SELECT/MENU
and the base ID code will be displayed on the
screen.
The handset provided with your E5640/E5655 is automatically
registered as Handset 1. Additional handsets will be assigned
numbers in the order they are registered (Handset 2, Handset 3,
or Handset 4). A maximum of 4 handsets can be registered to
the same telephone base.
The E5643B has 3 handsets automatically registered as handset
1, 2 and 3. You can register one additional handset, which will be
called Handset 4.
Enter base ID, then press SELECT.
ENTER BASE ID
NOTE: A maximum of two handsets or one handset and the
speakerphone on the telephone base can be connected to an
external line anytime.