Allow for a swift diversion of inbound calls to your chosen number in any scenario from power loss to telephone system failure, line fault or simply the inability to sufficiently staff your offices due to extreme weather.
No delay on applying the divert.
Risks of not having it
Could wait up to 24 hours before a divert is applied in the event of a power failure. If it is due to on site equipment failure BT OR will not put a divert in place, so customer could potentially be offline for days.