Millions of Brits will be startled by their phone on Sunday. Here’s why

By Trevor Mogg Published September 6, 2025

Brits enjoying a quiet Sunday today will be briefly interrupted this afternoon when the government tests its emergency alert system.

It means that at 3 p.m. some 85 million phones across the nation will suddenly start vibrating while also making a loud siren sound for about 10 seconds — even if they’re on silent.

The alert will also include a message on the display clearly stating that it’s an emergency test. So don’t panic.

Such alerts can be used to warn people of nearby dangers, such as severe weather events like storms or flooding. 

Indeed, the government said that since the first national test in 2023, the system has sent five real alerts during major storms when lives were genuinely at risk.

It also noted that some older phones or those not connected to 4G or 5G networks may not be compatible with the system and so will not receive the alert. More information about device compatibility can be found at gov.uk/alerts.  

Similar smartphone-based emergency systems are also operational in other countries, including the U.S., with regular tests carried out at various times. Finland, for example, tests its system monthly, while Germany, on the other hand, runs tests once a year.

“Emergency alerts have the potential to save lives, allowing us to share essential information rapidly in emergency situations including extreme storms,” lawmaker and senior government member Pat McFadden said earlier this year when the test date was announced. “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.”

When the U.K. carried out the first such test two years ago, it didn’t go so well. Some people got the alert earlier than the stipulated time, while other phones just stayed silent after failing to receive the alert. Hopefully the authorities have ironed out the kinks by now so that Sunday’s test will proceed exactly as expected. 

While the government recommends that folks keep the emergency alerts function enabled, you can also opt out of receiving them in a few simple steps.