HM Revenue and Customs (HMRC) has reported 11 ‘serious’ personal data incidents to the Information Commissioner’s Office (ICO) in the most recent financial year, according to official figures.

The incidents, disclosed in HMRC’s newly published annual report, are estimated to have affected 23,173 people in total and have been analysed by litigation practice Griffin Law.
The most severe incident occurred in February 2020, when a fraudulent attack resulted in 64 employees’ details being obtained from three PAYE schemes. Name, contact details and ID data, such as passwords and usernames, were leaked, and an estimated 573 people are said to have been impacted as a result.
According to the report, which was released on November 5, the affected customers had not yet been contacted, but the incident is still under investigation.
Other data incidents documented by HMRC in their annual report include a cyber attack against an agent and their client data, affecting 25 people; an incorrectly accessed tax payer record, and resulting refund to the taxpayer’s mother; leak of addresses and property details due to usage of the incorrect Excel spreadsheet, and, leak of medical documents, private correspondence and company data due to paperwork being left on a train.
A further 3,616 ‘centrally managed’ security incidents were also recorded; however specific details of these incidents were not revealed.
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HMRC stated the following in the report: “We deal with millions of customers every year and tens of millions of paper and electronic interactions. We take the issue of data security extremely seriously and continually look to improve the security of customer information. We investigate and analyse all security incidents to understand and reduce security and information risk. We actively learn and act on our incidents. For example, by making changes to business processes relating to post moving throughout HMRC and undertaking assurance work with third party service providers to ensure that agreed processes are being carried out.”
Human error
Cybersecurity expert Tim Sadler, CEO, Tessian commented: “Human error is the leading cause of data breaches today. And given that people are in control of more data than ever before, it’s also not that surprising that security incidents caused by human error are rising.
“That’s not to say, though, that people are the weakest link when it comes to data security. Mistakes happen – it’s human nature – but sometimes these mistakes can expose data and cause significant reputational and financial damage. It’s an organisation’s responsibility, then, to ensure that solutions are put in place to prevent mistakes that compromise cybersecurity from happening – alerting people to their errors before they do something they regret.”
“Taxpayers have a right to expect their sensitive personal data to kept secure by the taxman,” said Donal Blaney, principle, Griffin Law. “The Information Commissioner should immediately investigate HMRC for these breaches and hold the taxman to account for this breathtakingly incompetence”.
Note: This article has been edited as we previously reported a serious personal data incident recorded as May 2020, when it did in fact occur in May 2019. National Insurance number letters relating to 16-year-old children were sent out with incorrect details, impacting up to 18,864 members of the public.