Emergency alert goes off as planned for millions of phone users, but not for everyone

The much-anticipated emergency alert has sparked confusion for many phone owners who failed to receive it, while the notification arrived early for some and late for others.

The trial of the system, which is designed to warn people if there is a danger to life nearby, took place at 3pm on Sunday, with a test alert being sent to every 4G and 5G device across the UK.

But for many mobile phone users, the alert never arrived.

Twitter was flooded with people saying they had not received the promised loud alarm.

Some reported it arriving slightly early, at 2.59pm, and others received it several minutes after the expected time of 3pm.

They included sports broadcaster Jake Humphrey, who tweeted a screenshot of his alert with the comment: "12 mins late. Which is kind of worrying."

There was speculation online that many people on the Three mobile network hadn't received the message, while others questioned the use of the system if it was only available for people with 4G and 5G devices.

On Sunday afternoon, Three tweeted: "We're aware that a number of customers have not received the test alert.

"We're working closely with the government to understand why and ensure it doesn't happen when the system is in use."

The Cabinet Office said it would be reviewing the outcome of the 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".

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A UK Government spokesman 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.”

The alert coincided with several major events, including the London Marathon – with footage posted on Twitter showing hundreds of phones going off – and Premier League ties between Bournemouth and West Ham, and Newcastle and Tottenham Hotspur.

The alert was widely advertised by the government and reported by the media, with deputy prime minister Oliver Dowden earlier dismissing concerns that people would "panic".

His comments came after one international expert in alarm systems said many people were likely to be "astonished" that it was so "up close and personal".

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But while some admitted it had caught them off-guard, others reported the alarm being less dramatic than they had expected, with one Twitter user writing: "Was expecting something a bit louder and shrill, but it did the business."

In Nottingham, some shoppers did not realise the emergency alert was happening – pouring doubt on the effectiveness of the government's campaign to warn people in advance.

Aisha Khan, 18, from Nottingham, said: "I had absolutely no knowledge about it.

"When the alarm went off, I actually thought it was an alarm that was going off in the shop that we were in at the time.

"I think it will be helpful if you know when it's going off and it all depends on what they are telling us about."

Anny Mundeli, 44, said she was concerned that older people and people who suffer from anxiety "might worry about" the alarm, "especially if it just goes off out of nowhere".

Mundeli, from Nottingham, said: "I knew about it but I feel like people who suffer from anxiety or depression might worry about it, especially if it just goes off out of nowhere.

"It's quite loud which can also scare older people, they might not know how to turn it off."

Donna Anderson, 38, voiced concerns that the alert could "scare or confuse" children as it had scared her at first.

She said: "Children have phones nowadays so it could scare them or confuse them.

"It scared me at first and I didn't know how to turn it off when it popped up on my phone."

The system had sparked concerns from domestic violence campaigners, who warned the test could put people in danger by revealing the location of secret phones hidden away by those at risk, as well as from motoring associations, who warned drivers not to get distracted by the alarm if they were behind the wheel.

The alert – the first of its kind in the UK – included a message that said: "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."

Phone users were prompted to acknowledge the alert by swiping or clicking the message before being able to continue.

People had previously been instructed how to turn off the alarm to ensure it wouldn't sound.

Earlier on Sunday, Dowden had denied the alert system test was an example of so-called nanny statism.

He told the BBC’s Sunday with Laura Kuenssberg programme: "I think, in future, people will be grateful that we tested the system and what I would say is that at 3pm, when this siren – which I should say is about the volume of a phone call going off – goes off, you don't need to do anything.

"It is just a test."

The entertainment and sport sectors had put plans in place to guard against disruption when the test went off, sounding an alarm on tens of thousands of phones in certain places.

Organisers of the World Snooker Championship paused play just before 3pm at the Crucible in Sheffield, resuming after the alert, while the Society of London Theatre said it had shared the government’s guidance with its members and advised them to tell attendees to turn off their phones to "minimise disruption to shows".

For cinemagoers, a Vue spokesperson said: "Before every screening at Vue, we encourage our customers to turn their mobile phones off in order to fully immerse themselves in the big screen experience."

The test on St George's Day coincided with major events including the London Marathon and Premier League ties between Bournemouth and West Ham, and Newcastle and Tottenham Hotspur, kicking off at 2pm.

Officials said they had worked with the Football Association and the marathon's organisers to make sure the impact of the test would be limited.