Sunday marked the second national test of the emergency alert system in the UK, but not everyone got the message
John Bett and Julia Banim
15:46, 07 Sep 2025
(Image: AFP via Getty Images)
At 3 pm today (Sunday, September 7), mobile phones across the UK emitted a loud siren-like sound as the Government conducted a nationwide test of an early warning system. This marks the second national test of its kind, with nearly everyone owning a mobile phone or tablet receiving the alert.
The alert is designed to warn Brits of potentially life-threatening disasters such as extreme weather events or terrorist attacks.
It’s estimated that almost 100 million phones received today’s alerts. However, not everyone was alerted, leading to some confusion.
Here’s why your phone may have remained silent while others around you were sounding off.
(Image: AFP via Getty Images)
Approximately 95 per cent of the population would have had the 4G or 5G access required for today’s test. Those with older phones connected to just 2G or 3G, or WiFi only, wouldn’t have received a message, reports the Mirror.
You also wouldn’t have been alerted if your device was switched off or in aeroplane mode at the time. Having your phone on silent wouldn’t have made a difference, as previously warned to domestic abuse survivors with secret phones.
It’s understood that the emergency alert would only have worked on iPhones running iOS 14.5 or later, as well as Android phones and tablets running Android 11 or later. If your phone or tablet isn’t running the latest software updates, then you may not have been alerted.
Today’s test alert represented the second-ever nationwide trial for British residents, following the inaugural test conducted in April 2023. During the initial deployment, mobile users received identical advance notification; however, it emerged that certain devices failed to receive the warning, a shortcoming that could prove fatal in genuine emergency scenarios.
(Image: World Rugby via Getty Images)
While emergency alerts have gained recognition primarily through testing exercises, the system has also been deployed during actual crisis situations. Throughout 2024, the technology was activated on several occasions.
January saw Leicestershire residents warned about severe weather conditions, whilst February witnessed the system facilitating the evacuation of approximately 10,000 Plymouth residents following the discovery of an unexploded Second World War bomb. Several months later, in May 2024, Cumbrian residents received alerts regarding dangerous flooding.
Recipients of today’s alert will have also received the following explanatory message: “This is a test of Emergency Alerts, a UK government service that will warn you if there’s a life-threatening emergency nearby. You do not need to take any action. In a real emergency, follow the instructions in the alert to keep yourself and others safe.”
For further information regarding the UK’s emergency alert system, visit GOV.UK.