Power cuts overtake ISP faults as the UK's top broadband outage cause — and 4.6m don't know their phone dies too

9 October 2026. Britain's broadband went down an estimated 26.7 million times in the past year — and for the first time, the likeliest culprit was not the provider. A survey of 2,000 UK adults commissioned by Uswitch and carried out by Opinium between 29 September and 2 October 2026 puts power cuts ahead of ISP faults as the single biggest cause of outages: 42% of those affected blamed a power cut, against 31% who blamed their provider and 31% their router. But the number that matters most for phone users is smaller and sharper. Of the 26% of respondents who already have a digital landline running through their broadband router, 32% — an extrapolated 4.6 million people — do not know that it stops working in a power cut.

When the power goes, the dial tone goes with it

Digital handsets typically plug into the router, so a digital phone inherits every weakness of the broadband supply — and the broadband inherits the building's electrics. The old analogue network was powered from the exchange, which is why a corded phone kept working through a local power cut; digital voice ends that default unless a battery backup is fitted. Most major providers supply one free to vulnerable customers, and others can buy one — but the survey suggests awareness, not hardware, is the bigger gap. There is a money caveat too: Ofcom's automatic compensation only covers provider-fault outages lasting longer than two working days, so a power-cut outage usually pays nothing. Among respondents hit by an outage, only 16% received compensation — down from 22% a year earlier — and 57% did not know they could even ask.

A continuity gap most small firms haven't priced in

The timing matters. The analogue network those expectations rest on closes on 31 January 2027 — 114 days from today — and the survey found rural premises, which are more exposed to storm damage, the worst hit: 63% of affected rural users lost service to a power cut, versus 28% in cities, while 43% of all respondents worry about winter outages ahead. Two moves close most of the gap. First, a battery backup for the router and handset — tested, because backups have failed when needed. Second, a routing layer that does not depend on the office being powered: a virtual phone number that forwards to mobiles keeps inbound calls alive when the premises go dark, on plans from free pay-as-you-go to £9.97 a month. The countdown, and what still runs on copper, is tracked in our PSTN switch-off guide and our look at the 350,000 business lines still on copper.

Related: Openreach's PSTN safety net keeps broadband alive · Openreach extends migration discounts to the switch-off's final day