Back-Up Phone Number - FiOS Digital Voice You can use FiOS® Digital Voice to set up a secondary contact phone number where your calls can be forwarded automatically in the event your FiOS Digital Voice service is not working.
This back-up will be invoked whenever an outage occurs. This would generally be due to two unique outages:
If electricity has not returned by that time, it will not be possible to make or receive calls, including emergency calls to 911. In your welcome letter Verizon mailed to you, there were stickers to place on the phones in your house informing you of this information. We strongly recommend you apply them to your phone so users are aware of this possible limitation.
*Important Note The Battery Back-Up Unit is designed to use a 12-Volt 7.2 Ah SLA (Sealed Lead Acid) battery. Use of a different battery type is not recommended since other battery types may impact the performance of your FiOS services. Verizon is not responsible for damages which result from use of an improper battery. Batteries may be obtained at verizon.com/fiosaccessories or at a third party retail vendor
See also: Related Calling Feature topics - FiOS Digital Voice