Overview

• Compatible 4G and 5G phones and tablets will vibrate and sound a siren for about 10 seconds with an on‑screen message confirming it is only a test.
• The government has published the exact wording of the alert and opt‑out instructions, with targeted guidance for domestic abuse survivors and accessibility materials.
• Motorists are urged not to touch their phones during the alert, as using a handheld device while driving can lead to a £200 fine and six penalty points.
• Officials expect the broadcast to reach roughly 95% of about 87 million phones, though devices that are off, in airplane mode, or on 2G/3G will not receive it.
• This second full-scale drill follows earlier delivery issues, including around 7% of compatible phones missing the 2023 test, and comes alongside a broader Resilience Action Plan led by COBR.