Lambeth council has notified the Information Commissioners Office – the authority dealing with data protection – following a mass email that, it says, “did not function as intended”.
The email was an invitation to register for the council’s online council tax service.
A second email from council chief executive Sean Harriss asked people who had received the email to delete it because some of them may have been able to see the email addresses of other Lambeth council tax payers.
“Despite taking suitable precautions in protecting individuals’ email addresses, the email did not function as intended,” said Harriss.
“Some recipients may have been able to see other customer email addresses attached to the item. We are sorry for this disclosure and are working hard with our technical partners to understand how this has happened.
“We take your data and privacy seriously. This issue will be fully investigated to prevent this from happening again. We have notified the Information Commissioners Office and will work with them as they conduct their own investigation into this incident.”