AT&T CL80101 Cordless Telephone User Manual

Adding and registering handsets
If registration fails, the system will automatically try to register
again. If registration fails after the third try, Registration failed
appears on the screen for a few seconds. This may take up to five
minutes to occur. Please start again from Step 1 on the previous
You cannot register a handset if any other system handset is in use.
To reset the telephone, unplug the power from the telephone base and the battery
from the handset, then plug them back in.
Registration and deregistration