Emergency Alerts in the UK: How They Work

What to expect

• A loud siren-like sound and vibration
• A message explaining the danger and action
• Delivery to compatible devices connected to participating 4G or 5G networks
• No need to install an app or subscribe

What affects delivery

• Phone compatibility and software
• Connection to a supported network
• Device settings
• Being switched off, in flight mode or outside coverage

Privacy

The alert system uses cell broadcast. The government does not need the recipient’s name, phone number or precise location to send an alert to a geographic area.

When an alert arrives

Stop and read it when safe. Follow the official instructions and check gov.uk/alerts for confirmation. Do not call 999 merely to ask whether an alert is genuine unless there is an actual emergency.

Accessibility and hidden phones

The alert sound can be distressing and may reveal a concealed phone. People at risk of domestic abuse should review official guidance and device settings in advance, while recognising that disabling alerts removes a safety channel.

Know what the alert can and cannot do

UK Emergency Alerts use compatible mobile networks to broadcast warnings to phones in an affected area. They do not require a separate app or the government to know the recipient’s name or number.

• A phone may miss an alert if it is switched off, in flight mode, outside compatible coverage or using unsupported settings or software.
• The alert sound does not prove that ordinary calls or data will work.
• Read the message and use the official link or GOV.UK alerts page to confirm instructions.
• Keep other warning routes for anyone whose device or accessibility needs may prevent receipt.

Do not call emergency services merely to ask whether an alert is genuine. Follow the message and official public information unless there is a real emergency.