The government will be carrying out a national test of the UK Emergency Alerts system on 7 September 2025 at 3pm.
The test alert will be sent to all compatible 4G and 5G mobile phones and compatible tablets across the UK.
This follows the first successful national test in April 2023.
Regular testing ensures the system is functioning correctly, should it be needed in an emergency.
The test is not intended to alert you to real danger and you will not need to take any further action.
An emergency alert looks and sounds very different to other types of messages you might receive on your phone. You’ll hear a loud, siren-like sound and your phone or tablet will vibrate.