De-registration
Replacing a headset
To de-register all headsets from the headset base
NOTES:
1.If the de-registration process was not successful, you may need to reset the system and try again. Remove the headset from the headset base and press ON/OFF. Place the headset back into the headset base. You may also reset by unplugging the power from the headset base, then wait a few seconds, and plug it back in.
2.You cannot de-register the headset(s) if another system headset is in use.
To de-register all headset(s) from an AT&T cordless telephone base
This procedure de-registers all the headset(s) and handset(s) registered to the cordless phone.
1.Press and hold 
HANDSET LOCATOR on the telephone base of the cordless phone until the IN USE light on the telephone base
turns on and starts to flash (at least 10 seconds), then release the 
HANDSET LOCATOR button.
2.Immediately press and release 
HANDSET LOCATOR again. You must press 
HANDSET LOCATOR while the IN USE light is still flashing. (The light flashes for about seven seconds. If the light stops flashing, start again with step one above.)
3.De-registration may take up to 10 seconds to complete. The ON/OFF light on the headset flashes twice every five seconds if de-registration was successful.
NOTES:
1.See your telephone user’s manual to re-register the handsets.
2.See page 7 of this manual to re-register a headset.
