At yesterdays (22/03) Technology and Science presentation someone asked about the UK governments new Emergency Alert text service which is due to be tested on Sunday April 23rd 2023.  Full details can be seen by clicking the link.

As we’ve seen in the US and elsewhere, the buzz of a phone can save a life.” Emergency services, transport officials, and the environment agency were all consulted in developing the tool. The US, Canada, Japan, and the Netherlands already have similar systems in place to warn people about severe weather events.

Alerts can be related to such things as extreme weather, major incidents, disasters like earthquakes and other life threatening  situations.

As noted in the above document the government does not need to know your phone number or location to send you an alert.  In an emergency, mobile phone masts in the surrounding area will broadcast an alert. Every compatible mobile phone or tablet in range of a mast will receive the alert.