Overview

• Phones will play a loud 10‑second sound, vibrate and display a bilingual message confirming it is a test and that no action is needed, with links to gov.uk/prepare and gov.uk/alerts.
• Devices that are switched off, Wi‑Fi‑only or on 2G/3G will not get the alert, and delivery is based on a user's current location rather than their home address.
• Officials say users should dismiss the message after it appears, and drivers are told to wait until they can stop safely before reading any alert.
• The system has been used five times since 2023 for severe weather, local flooding and an unexploded WWII bomb in Plymouth, following an initial national test in April 2023.
• A public information campaign includes guidance for vulnerable people, with charities warning the test could expose hidden phones used by abuse victims and some MPs calling for additional non‑phone channels.