UK to test national emergency alert at 3pm; ministers urge calm amid health and safety concerns

The UK will carry out a nationwide test of its Emergency Alerts system at 3 p.m. BST on Sunday, September 7, sending a 10-second siren-like sound, vibration and on-screen message to 4G- and 5G-enabled phones and tablets. Ministers urged the public to remain calm and treat the exercise as a routine check of a system intended to deliver life-saving information during rare, life-threatening incidents.

Secretary of State for Work and Pensions Pat McFadden said the exercise is comparable to a fire drill and designed to ensure the system "works well when we need it most." The government said the test will be the largest public safety exercise of its kind in the UK and that officials will work with mobile network operators afterwards to assess performance.

The alert will be sent automatically over mobile networks and does not require phone numbers or the storage of personal contact details. The government said data about individuals or their devices will not be collected or shared during the test, and that phones will display a message making clear the notification is a drill and not an actual threat to life. Officials estimate there are about 87 million mobile phones in the UK and say roughly 95 percent of the population has 4G or 5G access.

Devices that are switched off, connected only to 2G or 3G networks, Wi-Fi-only tablets or phones that are not compatible will not receive the test. The system was launched in 2023 and this is the first nationwide test in two years. Emergency Alerts have been used in several real incidents, including issuing warnings to 4.5 million people in Scotland and Northern Ireland during Storm Éowyn and helping to evacuate more than 10,000 people in Plymouth after an unexploded Second World War bomb was discovered.

Despite government assurances about the test's purpose and technical safeguards, charities and some clinicians have warned of risks associated with the sudden alarm. Nicola Swanborough, head of external affairs at the Epilepsy Society, said loud noises can trigger seizures for some people with epilepsy. An expert in acute stress responses cited research suggesting that emergency alarms can cause heart rates to spike in some participants, saying the sound could provoke a "fight-or-flight" reaction that poses a risk, albeit a rare one, to vulnerable individuals.

Campaigners also raised concerns that the alert could inadvertently expose concealed phones used by victims of domestic abuse, potentially endangering people who rely on hidden devices to seek help. The government said it will continue engagement with domestic violence organisations and that people who need to avoid alerts can opt out on their devices.

Instructions provided by government guidance say iPhone users can disable test notifications by opening Settings, selecting Notifications and turning off "Severe Alerts" and "Extreme Alerts" at the bottom of the menu. Android users are advised to search device settings for "Emergency Alerts" and switch off the corresponding categories. The government recommends contacting device manufacturers for help if alerts continue after opting out, and notes that settings may be labelled differently depending on phone model and software version.

Officials highlighted accessibility features designed to reach people who are deaf, hard of hearing, blind or partially sighted, noting that audio, vibration and on-screen notifications will be used if accessibility notifications are enabled on a user’s device. They also reminded drivers of legal restrictions on using hand-held devices while driving and advised finding a safe place to stop before reading an alert.

Similar cell-broadcast systems are used in other countries. Japan operates a sophisticated combined satellite and cell-broadcast network as part of its J-ALERT system, and South Korea and the United States deploy national cell-broadcast or wireless emergency alert mechanisms for weather, civil emergencies and other critical information. The government said regular testing of the UK system is intended to ensure readiness in the event of severe flooding, widespread fires, terror attacks or other rare but life-threatening emergencies.

The test comes after a national exercise earlier in the year and follows public information campaigns across transport hubs, museums, GP surgeries, cultural venues and roadways to notify people in advance. Some organisations have taken steps to reduce disruption during performances and events; the Globe Theatre announced it would pause a performance of Twelfth Night so the alarm does not interrupt the show.

After the test, officials said they will review technical performance with mobile network operators and use findings to inform any adjustments to the system. The government reiterated that the alert is a tool for public safety and will be used only in circumstances where there is a danger to life nearby.

For those seeking further information, the government’s Emergency Alerts web pages provide details about the test, opt-out procedures and guidance for specific groups, including people with accessibility needs or those at risk from domestic abuse. The Department for Work and Pensions and the Cabinet Office said they will continue outreach to charities and vulnerable communities in the run-up to and following the exercise.