At around 3pm on this day, mobile phones connected to 4G and 5G networks will vibrate and emit a siren sound for up to 10 seconds.
Mobile phone users will also receive a message making clear that the alert is a drill.
This is a system that provides warnings and advice in the event of a life-threatening emergency, with the last test having taken place on April 23, 2023.
What is an Emergency Alert? Swipe through to find out.
🚨 There will be an Emergency Alerts test on Sunday 7 September at 3pm across compatible mobile phones and tablets in the UK. pic.twitter.com/q1XunMfY0J
— GOV.UK (@GOVUK) September 3, 2025
Emergency planners in the Cabinet Office Briefing Rooms (COBR) Unit have carefully chosen the time for the largest UK public safety exercise of its kind to minimise disruption.
Ahead of the alert, Pat McFadden, the Minister for Work and Pensions and previous Chancellor of the Duchy of Lancaster, has shared that he knows Brits will deal with the alert with no issue.
In a statement, he said: “I know Brits will keep their cool when phones across the UK make a siren-like noise today [Sunday] at 3pm. It’s important to remember this is only a test, just like the fire drills we all do in our schools and workplaces.”
“We’re carrying out the test to make sure the system works well when we need it most, and afterwards, we’ll work with mobile network operators to assess performance.
“The test takes just ten seconds, but it helps us keep the country safe 24 hours a day, 365 days a year.”
There will be an Emergency Alerts test on Sunday 7 September on compatible mobile phones and tablets across the UK.
Watch to find out what will happen on Sunday 🚨 pic.twitter.com/OPzx5lzVFc
— GOV.UK (@GOVUK) September 5, 2025
Emergency Alerts have been used in five real emergencies, including Storm Éowyn this January, when 4.5 million people across Scotland and Northern Ireland received one.
In Plymouth last year, it was used to evacuate more than 10,000 residents after an unexploded Second World War bomb was discovered.
Mobile phones that will receive the emergency alert
Emergency alerts will only work on the following devices:
- iPhones running iOS 14.5 or later
- Android phones and tablets running Android 11 or later
Other phones that do not run iOS or Android may also receive alerts.
You may also still be able to receive alerts if operating on an earlier version of Android.
To check, search your device settings for ‘emergency alerts’.
You will not receive an emergency alert message if your device is:
- Turned off
- Connected to a 2G or 3G network
- Wifi only
- Not compatible
- In airplane mode
At 3pm Sunday, 7 September, the government will test their Emergency Alerts system. It’s designed to get urgent messages to people when a nearby emergency happens. If you need to avoid the alarm going off for any reason, turn your phone off. Share this post to spread the word. ⚠️ pic.twitter.com/CtuYXTRjZY
— British Red Cross 🧡 (@BritishRedCross) September 4, 2025
How to opt out of emergency alert tests
If you do not wish to receive an emergency alert message as part of the national training, you can opt out.
Android phones
To stop receiving operator test alerts on Android devices, search your phone’s settings for ‘emergency alerts’ and turn off ‘test alerts’, ‘exercise alerts’, ‘operator defined’, and ‘operator alerts’.
If you cannot see them in your settings, the government says to:
- Opening your phone’s calling app
- Using the keypad to enter *#*#2627#*#*
- Search your settings for ‘emergency alerts’ and turn off ‘test alerts’, ‘exercise alerts’, ‘operator defined’ and ‘operator alerts’
iPhones
If you have an Apple iPhone, head to settings, notifications, messages, and then slide the ‘Critical Alerts’ toggle to off.
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Other mobile phones
Depending on the manufacturer and software version of your phone, emergency alert settings may be called different names, according to Gov.uk.
The settings can usually be found in one of the following ways. The government website says to go to:
- ‘Message’, then ‘message settings, then ‘wireless emergency alerts’, then ‘alert’
- ‘Settings’, then ‘sounds’, then ‘advanced’, then ‘emergency broadcasts’
- ‘Settings’, then ‘general settings’, then ‘emergency alerts’
“Then turn off ‘test alerts’, ‘exercise alerts’, ‘operator defined’ and ‘operator alerts’,” it adds.
