Phone signal outages during a power cut are getting fresh Ofcom rules
Ofcom published new guidance in June 2026 covering phone signal outages when the power goes down. It fills a gap that had sat largely blank since 2024: what exactly mobile networks are expected to do to keep your phone connected when the electricity supplying their masts fails.
Here’s the thing that catches most people out. Your phone doesn’t run on electricity from your house. It runs on a signal from a mast, and that mast needs its own power. Cut the power to enough masts, and your phone goes quiet even though your phone itself is fully charged.
Why do phone signal outages happen in a power cut at all?
Mobile masts need continuous power to broadcast a signal, same as anything else plugged into the grid. Most already carry some battery backup, enough to ride out a short outage, but not every mast is built the same way, and coverage in a prolonged cut has always been patchy.
Ofcom’s new guidance pushes mobile networks to document a proper risk assessment for each site and match their backup investment to it, rather than leaving resilience to chance. Notably, it stops short of setting one fixed number of backup hours for every mast in the country.
Why didn’t Ofcom just set a fixed number of backup hours?
Earlier proposals floated requiring at least an hour of battery backup at mobile mast sites. Mobile network operators pushed back hard, arguing the cost and practicality varies wildly between a mast on a busy high street and one halfway up a Welsh hillside.
Ofcom’s compromise is a risk based approach instead. Each network has to assess its own outage risk, document it, and invest accordingly, with Ofcom checking whether that assessment is current and matched to what’s actually been spent. A final statement is expected in autumn 2026.
What should you actually do about phone signal outages?
Not much changes for you today. This guidance shapes what networks build over the coming years, not something you need to act on this week. But a few sensible habits are worth having regardless of what Ofcom decides.
Keep a basic backup plan for the genuinely bad days: a portable charger, a wind up radio, or simply knowing your nearest landline or a neighbour with a different network. If you or someone in your household relies on a phone for medical alerts or care calls, it’s worth checking your supplier’s Priority Services Register.
Does this affect every mobile network the same way?
In principle, yes. The guidance applies across EE, Three, Vodafone and O2, plus the virtual networks that run on their infrastructure. In practice, how quickly each operator upgrades its weakest sites will vary, and Ofcom hasn’t published network by network backup figures.
Rural and coastal areas, where masts are more spread out and harder to reach for maintenance, are generally the ones with the least backup margin. If you already know your signal drops during storms or grid issues, that’s not new information Ofcom’s guidance is confirming, not creating.
Phone signal outages and power cuts, at a glance
- New Ofcom guidance published 16 June 2026, covering power backup at mobile mast sites.
- No fixed number of backup hours required, a risk based approach instead.
- Networks pushed back against an earlier proposed one hour minimum.
- Final Ofcom statement expected autumn 2026.
- Rural and coastal masts tend to have the least backup margin today.
Frequently asked questions about phone signal outages and power cuts
- Will my phone signal always fail in a power cut?
- Not necessarily. Most masts already carry some battery backup, so a short local power cut often doesn’t affect your signal at all. Longer or wider outages are where the gaps tend to show.
- Does this Ofcom guidance apply to broadband too?
- The June 2026 guidance covers mobile radio access networks specifically, though Ofcom’s broader network resilience expectations also touch broadband and fixed line providers separately.
- Can I ask my mobile network how much backup my local mast has?
- You can ask, though most networks don’t publish site by site backup details, partly for security reasons. Your best bet for a general answer is your provider’s customer service team.
- What’s the Priority Services Register got to do with mobile signal?
- It’s primarily an energy and water scheme, but registering flags you as needing extra support during power cuts, which can matter if you depend on a phone signal for medical or care alerts.
- Is 999 access protected even without normal signal?
- UK phones can attempt an emergency call on any available network’s signal, not just your own provider’s, though this only works if at least one network’s mast in your area still has power and coverage.
Phone signal outages during a power cut are one of those things you only think about once it’s already happened. Ofcom’s guidance won’t fix every gap overnight, but it’s the first time backup at mast sites has had a proper, documented expectation behind it rather than a shrug.
