GOV.UK CORONAVIRUS ALERT. New rules in force now: you must stay at home. More info and exemptions at gov.uk/coronavirus Stay at home. Protect the NHS. Save lives.
Some customers have already received the message, while others are set to get it later in the day.
The government has had to work with the operators to get the message sent because an emergency alert system, trialled seven years ago, was never put into practice.
While the link in the government text is safe to click, the public is being warned to be cautious about other unsolicited coronavirus messages they receive.
The UK’s National Cyber Security Centre has warned that criminals have ramped up bogus email campaigns that aim to trick users into clicking links that can lead to their computers being infected or seek to fool the recipients into divulging sensitive information.