Kathrine Frich
It’s designed to be impossible to miss.
It’s designed to be impossible to miss.
Millions of Phones to Sound Siren
On Sunday, September 7 at 3pm, millions of UK phones will blare a 10-second siren, vibrate, and flash a message as part of a government test of its national emergency alert system.
The aim? To prepare the public for future disasters, terror attacks, or even war.
No Signal? No Problem. It’ll Still Go Off
The alert doesn’t require WiFi or mobile signal to activate. However, it won’t work on 2G or 3G phones or devices that aren’t compatible with the alert system.
There are an estimated 87 million phones in the UK, and most will receive the test alert.
It’s Loud Even If Your Phone Is on Silent
The test alert will override your settings. So even if your phone is on Do Not Disturb or silent mode, the siren will still play at full volume.
It’s designed to be impossible to miss, just like a fire alarm in your home.
Brits Warned: Be Ready for the Blast
Government officials are urging the public not to panic when the siren hits.
Instead, they want people to recognize the alert as a life-saving tool that could one day warn them of extreme weather, national emergencies, or even a military threat.
The First Test Was Just the Beginning
This will be the second national test of the system, with more trials planned.
The government says these will happen regularly to ensure the public knows what to expect — and to work out any technical bugs before a real emergency strikes.
It’s Already Been Used for Real Warnings
Since its rollout, the alert system has been activated in real-world emergencies.
In January 2025, during Storm Éowyn, 4.5 million people in Scotland and Northern Ireland received alerts about dangerous conditions.
Stock Up: Government Urges Brits to Be Prepared
Officials are also encouraging the public to stockpile essentials like medicine, bottled water, and tinned food as part of its wider “Plan for Change” strategy.
The government is rolling out major investments in national resilience.
What’s Behind the Alert Push?
The alert system is part of a £1 billion biosecurity initiative, which includes a new network of National Biosecurity Centres, a £4.2 billion flood defence scheme, and a sweeping Resilience Action Plan to protect the UK from future shocks.
Government Says It’s All About Saving Lives
Chancellor of the Duchy of Lancaster Pat McFadden defended the test, saying it’s about building resilience and “securing the nation.”
He stressed that alerts can warn of deadly storms and other disasters, potentially saving countless lives.
New Tech, Tougher Networks
The UK is also investing £370 million in telecoms resilience, researching ways to protect infrastructure from cyber threats and ensure robust communications during national emergencies.
