INTERTWINE TESTING SERVICES 8.0 Security code information The telephone has an internal security code with 65,536 possible combinations. Each time you pick up the HANDSET, the code is randomly set to a new combination. Communication between HANDSET and BASE UNIT may not be possible in any of the following situation: 1. After a power failure. 2. After relocation the BASE UNIT by disconnecting the AC adapter. 3. After replacing the HANDSET battery.