Emergency alert: Three responds after phone users complain they did not receive test

The network said it was working with the government to assess the issue

Millions of phones across the UK sounded a siren on Sunday as part of a test for a new national emergency alert system.

Although the loud alarm was planned to activate at 3pm on all devices using 4G and 5G networks in the UK, some phone users, including a number of those on the Three network – one of the largest in the UK – complained that they had not received the alert.

The alert sounded for 10 seconds and displayed a message notifying phone users that no action was needed in response to the test.

Moment emergency alert test goes off at London Marathon (PA)

The message read: “This is a test of Emergency Alerts, a new UK government service that will warn you if there's a life-threatening emergency nearby.

“In a real emergency, follow the instructions in the alert to keep yourself and others safe.

“Visit gov.uk/alerts for more information. This is a test. You do not need to take any action.”

In a statement, a Three spokesperson said: “We are aware that a number of customers have not received the test alert. We are working closely with the government to understand why and ensure it doesn’t happen when the system is in use.”

A cosplayer holds up his mobile phone as the test message is displayed during a sci-fi event in Scarborough (PA)

One social media user said: “Well that was disappointing, no #emergencyalert on mine or my husbands phone and yes we do have them turned on.”

Another added: “No alert on my pixel 6 pro, though I’m seeing I’m not the only one. And nothing on my Nans old iPhone either even though it’s on iOS 12. Slightly odd!”

The system is intended to be used in life-threatening situations, including floods and wildfires, but some Britons have now raised concerns about the effectiveness of the system, given a large proportion of people did not receive the test.

The message was sent to 4G and 5G mobile phones, causing the devices to emit a sound and vibrate for up to 10 seconds. Phone users were prompted to acknowledge the alert by swiping or clicking the message before being able to continue using their device.

The emergency alert goes off in Westminster (PA)

The Cabinet Office said it would be reviewing the outcome of the UK-wide test of the new alert system.

The department said that, while the vast majority of compatible phones received the alert, officials were aware that a “very small proportion of mobile users on some networks did not receive it”.

It said that the matter would be looked into as part of the review of Sunday’s test.

A government spokesperson said: “We have effectively completed the test of the UK-wide Emergency Alerts system, the biggest public communications exercise of its kind ever done.

“We are working with mobile network operators to review the outcome and any lessons learned.”