From North Northants Council via Titchmarsh Parish Council

There will be a national test of the UK’s new Emergency Alerts system on Sunday April 23rd at 15:00.

The test alert will be sent to most mobile phones across the UK. Devices will make a distinct, siren-like sound for up to 10 seconds, including on phones switched to silent mode. Phones will also vibrate and display a message about the test. You can hear an example of what the test will look and sound like in our explainer video.

Note: If you’re a domestic abuse survivor with a concealed phone, the alert could reveal your phone, even if it’s on silent.