Tip 1 of 1

When first purchased, all accessory handsets show NOT REGISTERED on the screen. To register a handset:
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Step 1: Place the handset in the base unit or a charger that is connected to a power outlet. If PRESS HNDST LOC 4 SEC ON BASE does not appear on the screen after a few seconds, lift up handset and place in base or charger again.
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Step 2: On the telephone base, press and hold HANDSET LOCATOR for four seconds. Release HANDSET LOCATOR once the IN USE light comes on.

Soon, the handset will emit a series of tones, and the successfully registered handset will be assigned the lowest extension number not previously assigned to another system handset. Repeat Steps 1 and 2 if the handset does not successfully register to the telephone base within two minutes.