UK mobile phones to sound emergency alert test on September 7

The UK government will send an Emergency Alert test to all mobile phones across the UK

The UK government will send an Emergency Alert test to all mobile phones across the UK at 3pm on Sunday 7 September 2025.

This will be the second ever national test of the Emergency Alerts system. The system is used to warn the public if there’s a danger to life nearby, including extreme weather. It allows vital information and advice to be sent to people rapidly in an emergency.

Since its launch in 2023, Emergency Alerts have protected communities during five real life  emergencies. For example, it alerted citizens to the Met Office’s red weather warning during Storm Eowyn in January 2025, and during flash flooding in Cumbria in May 2024.

What will the test look like

On Sunday 7 September at around 3pm, mobile phones and tablets on 4G and 5G networks across the UK will vibrate and make a loud siren-like noise for roughly ten seconds, even if set to silent mode. A message will appear on screens clearly identifying the alert as a test only - you do not need to take any action in response to the test alert. There are approximately 87 million mobile phones across the UK.

The alert message will also point the public to gov.uk/prepare, a one-stop site offering practical advice about steps households can take to prepare for emergencies.

Why the Government is carrying out a test

It’s important to test the Emergency Alerts system regularly to make sure it works effectively in real emergencies. Tests also help people become familiar with what an alert looks like. This is in line with standard practice in other countries, such as Japan and the USA.

Who needs to know about the test

The UK government is running a public awareness campaign ahead of the test on 7 September to notify people it is taking place. Accessible materials, including British Sign Language videos and Easy Read content, have been produced as part of the campaign.

The campaign includes targeted communications to drivers and potentially vulnerable groups, such as domestic abuse victims who may have concealed phones. There is an opt-out option available for those who need it, but emergency alerts contain life-saving information and should be kept switched on for your own safety. Those driving at the time of the test should find somewhere safe and legal to stop before reading the message.

For more information, please visit gov.uk/alerts.