UK Government Confirms Date for National Emergency Alert Test in September
Millions of mobile phone users across the UK will receive a loud siren alert as part of a national test of the Government’s Emergency Alert system.
The UK Government has announced that the next nationwide test of its Emergency Alert system will take place at 3pm on Sunday, 7 September, 2025. The alert will be sent to all 4G and 5G compatible mobile phones, sounding a loud siren and causing devices to vibrate for around 10 seconds—even if phones are on silent. A message will also appear on the screen, making it clear that the alert is only a test.
The Emergency Alerts system was launched in April 2023 and is designed to rapidly warn the public of life-threatening situations, such as severe weather events, fires, and public safety threats. It has already been used several times, including during Storm Darragh in December 2024, when alerts were sent to over three million people amid winds of up to 90mph.
This upcoming test will be the second national test of the system. The Government says regular testing is essential to ensure the system functions properly and that the public knows what to expect during a real emergency.
“Emergency Alerts have the potential to save lives, allowing us to share essential information rapidly in emergency situations including extreme storms,” said Pat McFadden, Chancellor of the Duchy of Lancaster. “Just like the fire alarm in your house, it’s important we test the system so that we know it will work if we need it.”
A public information campaign will run in the weeks leading up to the test, including materials aimed at vulnerable groups—such as victims of domestic abuse—and content in British Sign Language to ensure accessibility.
Since the system’s launch, five real alerts have been issued, including:
• Storm Éowyn in January 2025, which triggered alerts for 4.5 million people in Scotland and Northern Ireland under a red weather warning.
• A warning during the discovery of an unexploded World War II bomb in Plymouth.
• Alerts for flash flooding in Cumbria and Leicestershire.
The system is based on similar alerting mechanisms used in countries such as the United States and Japan.
The test on 7 September forms part of the Government’s broader strategy to strengthen national resilience, which includes over £4 billion in flood defence investment and £1 billion towards National Biosecurity Centres.
What to Expect on 7 September:
• Time: 3:00pm
• Duration: Around 10 seconds
• Who will receive it: All 4G and 5G phones in range
• What it looks like: Loud siren sound, vibration, and a message on screen saying it is a test
For anyone concerned about privacy or safety—such as those in sensitive living situations—the alert settings on phones can be managed, and further guidance is expected to be provided during the public awareness campaign.