The government will send an emergency alert test to millions of Brits within months.
Phones across the UK will emit a loud siren at 3pm on Sunday, 7 September as part of the second national test of the government’s system.
The drill will send a loud, 10-second sound and vibration to 4G and 5G mobile phones, even if they are set to silent, alongside a message that will appear on screens making clear it is only a test.
The system is designed to warn people of life-threatening situations such as severe weather, floods or other major emergencies. The test is intended to familiarise the public with how the system works and ensure it functions correctly.
The first UK-wide test took place in April 2023. Since then, the system has been used five times, including during Storm Éowyn in January 2025, when over 4.5 million people received an alert. Alerts were also issued during Storm Darragh, which caused two deaths, and in response to a WWII bomb discovery in Plymouth.
When will the test be?
Pat McFadden, chancellor of the duchy of Lancaster, said: “Emergency alerts have the potential to save lives, allowing us to share essential information rapidly in emergency situations including extreme storms. 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.
“This test is part of our action plan to build resilience across the whole country and secure the nation under the Plan for Change – from the £1 billion we’re investing in a new network of National Biosecurity Centres to the £4.2 billion we’re investing to build a new generation of flood defences to protect local communities.”
Béatrice Butsana-Sita, the CEO of the British Red Cross, said: “The government has set out a strong plan to improve the country’s preparedness, with recognition of the important role played by the voluntary sector and the need for a ‘whole of society’ approach so no-one is left behind.
“We know from our work across the UK that people often don’t know how to prepare for a range of emergencies and can struggle to get back on their feet afterwards. Having tailored and targeted advice for people, especially those who may be more at-risk, could help reduce the impact of crises and even save lives.
“The real test will be how this translates into tangible action, down to community and household level, so that we aren’t just warned but prepared and everyone is ready to respond in an emergency.”
How many mobile phones are there in the country?
There are approximately 87 million mobile phones in the UK, according to the government.