Reminder – Tomorrow is a Nationwide Mobile Test of UK Emergency Alerts
Just a reminder that the UK government will conduct another major nationwide test of the Emergency Alerts service at 3pm tomorrow (Sunday 7th September 2025), which will be sent out via mobile networks to supporting handsets. This is otherwise normally only intended to be used if there’s a “danger to life nearby” (severe flooding, fires and extreme weather etc.).
The last national test took place on 23rd April 2023 and helped to identify a number of issues. But it’s since been used on several other occasions, albeit in a more localised way, to help warn of several major storms and floods (e.g. Storm Éowyn in Northern Ireland and parts of Scotland during January 2025). You can see a Summary of Past Emergency Alerts on the government’s official website.
Systems like this need to be tested on a regular basis to ensure they’re working properly and to help familiarise the population with their function. The alert itself typically manifests as a loud 10-second siren sound blaring out at you from your mobile phone (even if it’s set to “silent“), which will also vibrate for the same period and display a message to say that it’s just a test of the Emergency Alerts system.
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The alerts themselves are broadcast from cell towers in the vicinity of an emergency (they don’t need your phone number for this to work) and will only ever come from the Government (i.e. departments, agencies and public bodies that deal with emergencies) or the emergency services. Such alerts are a free one-way secure communication and do NOT reveal anyone’s location or collect personal data.
The exact message structure of the September 2025 test is not yet known, but the original one in April 2023 is pictured at the top of this article and we’d expect the new test to follow a similar style. People at risk of domestic violence or whom simply don’t want to be bothered by the alert can opt-out here, but we’d generally otherwise recommend that people keep it enabled for obvious reasons.
Officially speaking, the government states that their alerts will work on Apple iPhones running iOS v14.5 or later and Android phones / tablets running Android v11 or later. But we have seen them being received by earlier versions, as well as devices other than Smartphones.
Finally, remember NOT to read or respond to an emergency alert while driving or riding – no matter how panicked it might make you, as doing so would be illegal (you need to find somewhere safe and legal to stop before reading the message).
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Mark is a professional technology writer, IT consultant and computer engineer from Dorset (England), he also founded ISPreview in 1999 and enjoys analysing the latest telecoms and broadband developments. Find me on X (Twitter), Mastodon, Facebook, BlueSky, Threads.net and Linkedin.
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I do wonder if it will broadcast over 5GSA or not, suppose I could always make sure my device is locked to 5GSA only prior to 3pm on Sunday. – I’ve received them before so if I don’t get it I’ll know that 5GSA isn’t supported.
Opted out the last time, I checked to make sure it has not changed for any reason and it is still opted out.
Lebara sent my mother a text giving advanced warning about the test, but I never got one. Be interesting to see if both our phones get the alert.
Of 20 or so phones I manage for one company only two have had the warning text. One had a second Lebara SIM and another a second SIM on EE. The rest (O2/Vodafone) have not received it.
Can confirm I know someone who has received the warning text on Lebara and I think I’ve seen someone on Vodafone get it too. I’ve had a text on O2 as well, I’ll attach it below:
O2UK on Tuesday at 11:28:
“Government Emergency Alert test: 7 Sept, 3pm. If your phone’s compatible, you’ll hear a siren and feel it vibrate. No action is needed. More info: [redacted link in case spam filters don’t like me, just the government alerts page]”
They’re also doing ads for this on YouTube with the siren sound actually playing which is startling people.
Having the govt sending things to people’s phones directly is such an orwellian thing. easiest opt out
I don’t know how the Japanese can live with their super advanced alert system for earthquakes and tsunamis! So Orwellian!
Normal people do not need the state to send a text on the phone, they can actually feel an earthquake
Ideally peopleare warned before the disaster happens.
The 307 people who drowned in the North Sea flood of 1953 knew the flood was happening when it was too late to move to safety.
It in part replaces the RIDE warning system that has been in the place since the 1980s that could call every landline telephone and play a recorded message to warn of hazards or disasters. As the penetration of landlines has dropped hugely a new system to warn people was needed.
Natural disasters happen. History has shown us that wars happen. It is entirely proper for a government to be able to alert lots of people, all at once, about things that could kill them and advise them how to move to safety.