Panasonic KX-FG2451 - Manual (Page 52)

9. Option
52
9 Option Cordless handset Registration
9.1 Re-registering the cordless
handset
The included cordless handset and base unit are
preregistered. If for some reason the cordless handset is
not registered to the base unit, register the cordless
handset.
Important:
L Make sure the base unit and the cordless
handset are near each other and not being used.
1 Cordless handset:
{MENU} i {0}{0}
L The rest of the procedure must be completed
within 1 minute.
2 Base unit:
Press and hold
{LOCATOR}.
3 Cordless handset:
Press
{OK} (soft key), then wait until the cordless
handset beeps.