Panasonic KX-TG5761S Operating Instructions Manual page 66

Useful Information
Problem
The 2nd caller's
information is not
displayed during an
outside call.
I cannot access the caller
list.
66
For assistance, please visit http://www.panasonic.com/phonehelp
Cause/solution
L In order to use Caller ID, Call Waiting, or Call Waiting
Caller ID (CWID), you must first contact your telephone
service provider and subscribe to the desired service.
After subscribing, you may need to contact your
telephone service provider again to activate this
specific service, even if you already subscribed to both
Caller ID and Call Waiting with Caller ID services
(CWID).
L Someone is viewing the caller list from another
handset.