Smartphones across the UK will receive an Emergency Alert at around 3pm on Sunday 7th September, as part of a routine test to help strengthen the country’s preparedness in a life-threatening emergency.

The UK’s Emergency Alerts system has been created to warn citizens if there’s a danger to life near them, including extreme weather or a terror attack.

In the upcoming test, approximately 87 million mobile phones will vibrate and make a loud siren sound for roughly ten seconds, even if the device is set to silent. A message will also appear, making it clear that the alert is a test.

This test will be the second of its kind, and follows a government commitment to test the system regularly to make sure it works optimally and to familiarise the public with the alerts. It’s in line with standard practice in other countries, such as Japan and the USA.

Since the first country-wide test of the Emergency Alerts system in April 2023, five alerts have been sent, including during major storms when lives were at risk.

The largest-ever use of the system saw over 4 million people in Scotland and Northern Ireland receive a mobile alert during Storm Éowyn in January 2025 after a red weather warning was issued, meaning there was a risk to life.

Other activations have included when around 3.5 million people across Wales and the South West of England received an alert during Storm Darragh in December 2024, and when an unexploded World War II bomb was discovered in Plymouth.

“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,” said Pat McFadden, Chancellor of the Duchy of Lancaster.

“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.”

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The news comes as McFadden unveils a new Resilience Action Plan to improve the way the government prepares for and responds to emergencies.

The Resilience Action Plan, to be published on Tuesday, sets out how the National Situation Centre and the devolved governments are going to sign a data sharing MoU to ensure that every nation in the UK has the best available data to prepare and respond to crises, among other measures.