Overview

• Compatible 4G and 5G phones and tablets will sound a 10‑second siren, vibrate and display a message stating, “This is a test of Emergency Alerts.”
• Older devices, phones on 2G/3G, switched‑off or airplane‑mode handsets will not receive the alert, and tourists in the UK with compatible devices will.
• The government has published opt‑out steps for iPhone and Android, with charities urging survivors using concealed phones to disable alerts in advance.
• Drivers are told not to handle phones during the alert, with motoring bodies warning that using a hand‑held device can result in a £200 fine and six penalty points.
• Ministers say delivery gaps seen in the April 2023 test were resolved, and the system has since been used five times for real incidents including major storms and a Plymouth WWII bomb.