Overview

• Phones nationwide are due to receive a government test message at about 3 p.m. on Sunday, 7 September, triggering a loud tone and vibration for roughly 10 seconds.
• Alerts will be broadcast to compatible 4G and 5G devices and will sound even if a phone is on silent, while devices that are off, Wi‑Fi only, or on 2G/3G will not get the test.
• Messages are targeted by a user’s current location via mobile masts, and devices do not need location services switched on to receive them.
• The published test wording appears in English and Welsh with links to gov.uk/alerts and gov.uk/prepare, and coverage estimates suggest about 87 million devices could receive it.
• Guidance explains how to opt out in phone settings, provides accessibility resources including BSL materials, highlights advice for domestic abuse survivors, and reminds drivers to read alerts only when safely stopped.