There will be a national test of the UK’s new Emergency Alerts system on Sunday 23 April at 15:00.
The test alert will be sent to most mobile phones across the UK. They will make a distinct, siren-like sound for up to 10 seconds, including on phones on silent mode. Phones will also vibrate and display a message about the test. The message will say:
"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."
For the test, the public does not need to take any action - the sound and vibration will stop automatically after ten seconds. All people need to do is swipe away the message or click ‘OK’ on their phone’s home screen - just like for a ‘low battery’ warning or notification - and continue to use their phone as normal.
Listen to an example of what the test will look and sound like in the government's short explainer video here.