ICO warns on use of ‘blind carbon copy’ email function after finding local government among worst offenders

The Information Commissioner's Office (ICO) has issued a warning to local government organisations to use alternatives to the blind carbon copy (BCC) email function when sending emails containing sensitive personal information, after finding councils are the third biggest offender for BCC data breaches.

The warning comes alongside the publication of updated guidance on email security, which sets out the law and good practice around protecting personal information when sending bulk emails.

BCC is an email function that allows a sender to copy numerous people into an email while keeping the email addresses of the recipients from appearing in the email header.

According to the data watchdog, local government is the third biggest offender for BCC breaches, with education first, health second and retail and the charity sector rounding out the top five.

According to ICO data, failure to use BCC correctly is consistently within the top 10 non-cyber breaches, with nearly a thousand reported since 2019.

The ICO has taken enforcement action over email breaches as recently as this month after finding two Northern Irish organisations disclosed people's information inappropriately by email.

Last month, the watchdog issued a reprimand to NHS Highland for a serious breach of trust after a data breach involving those likely to be accessing HIV services.

Commenting on BCC breaches, Mihaela Jembei, ICO Director of Regulatory Cyber, said: "While BCC can be a useful function, it's not enough on its own to properly protect people's personal information. We're asking organisations to assess the nature of the information and the potential security risks when deciding on the best method to communicate with staff or customers. If organisations are sending any sensitive personal information electronically, they should use alternatives to BCC, such as bulk email services, mail merge, or secure data transfer services.

"This new guidance is part of our commitment to help organisations get email security right. However, where we see negligent behaviour that puts people at risk of harm, we will not hesitate to use the full suite of enforcement tools available to us."

The guidance published today (30 August) notes that data protection law says that organisations must have appropriate technical and organisational measures in place to ensure personal information is kept safe and not inappropriately disclosed to others.

It also states that organisations that use and share large amounts of data, including sensitive personal information, should consider using other secure means to send communications, such as bulk email services, so information is not shared with people by mistake. 

Organisations should also consider having appropriate policies in place and training for staff in relation to email communications, the guidance adds.

The guidance also notes for non-sensitive communications, organisations that choose to use BCC should do so carefully to ensure personal email addresses are not shared inappropriately with other customers, clients, or other organisations.

Adam Carey