Britain’s new emergency alert service will be tested at 3pm on Sunday 23 April.
The siren-style alarm is set to be used in “life-threatening situations” such as extreme weather, flooding and fires according to the government, though it is said to be unlikely to be used during an active terror attack – as the attackers would then also receive a notification.
Cabinet Office minister Oliver Dowden said the alert could one day "be the sound that saves your life".
Messages will ping up on mobile phones across the nation and a sound and vibration that will stop automatically after 10 seconds.
Phone users will need to tap ‘OK’ or swipe away the notification without any further action needed.
The government said in a statement: “Emergency Alerts is a UK government service that will warn you if there’s a danger to life nearby.
“In an emergency, your mobile phone or tablet will receive an alert with advice about how to stay safe.
“The government does not need to know your phone number or location to send you an alert.”
The alert will make a sound even if a person’s phone is switched on to silent and it is the first nationwide trial of the service after trials pilots in East Suffolk and Reading.
Emergency alerts will only be sent by the emergency services, government departments, agencies and public bodies that deal with emergencies.
Your mobile phone or tablet may make a loud siren-like sound, even if it’s set on silent, vibrate or read out the alert.
The alarm will include a phone number or a link to the Gov.uk website for more information, which said: “You’ll get alerts based on your current location – not where you live or work. You do not need to turn on location services to receive alerts.”
It added: “If you have a vision or hearing impairment, audio and vibration attention signals will let you know you have an emergency alert.”
The alert has been in production for about three years and notifications could be sent to specific areas – such as residents of a village where a river was about to burst its banks.
Similar services are already in use in the US, Canada, the Netherlands, Greece and Japan.
