Overview

• The 86-word test message warns of potential life-threatening emergencies and directs recipients to gov.uk/prepare and gov.uk/alerts for further guidance.
• Scheduled for around 3pm on 7 September, the alert will override silent mode on all 4G and 5G phones nationwide, emitting a 10-second siren and vibration.
• The government has rolled out a public awareness campaign featuring British Sign Language videos and targeted outreach to vulnerable groups, including domestic-abuse survivors.
• This exercise marks the system’s second nationwide test since its April 2023 launch, following real-world activations during severe storms and a World War II bomb threat.
• MPs such as Sarah Olney are urging ministers to introduce non-phone channels, like printed pamphlets, to reach those without mobile access.