No, your Hub must have power for you to be able to make calls using our Digital Voice service.
If there's a power cut, please make calls using an alternative method, such as a mobile phone.
If you live in an area with poor mobile coverage or somewhere prone to power cuts, you can buy a battery back-up unit (BBU) when ordering Digital Voice or from BT Shop >
There are 2 versions of the Battery Backup unit, one for customers with Copper delivered BB service and one for customers with Fibre to the home delivered Broadband service, be sure to select the correct one.
If you have a battery back-up unit, both broadband and voice services will continue to work for up to an hour if there's a power cut. Please make sure you keep your battery back-up unit connected to the mains power supply and your Hub powered up. This will make sure it has enough charge if it's needed..