The UK’s Post Office Horizon IT scandal was one of the UK’s greatest miscarriages of justice involving IT and the public in Britain. It resulted in more than 700 sub-postmasters and postmistresses charged or prosecuted for theft – even though financial losses were judged much later to be the consequence of a defective Horizon IT system. Beyond reputational damage, false criminal charges, and damaged lives, up to 13 suicides have been linked to this scandal (Brooks 2025: 3).
The IT system’s problems stemmed from software developed as early as 1999. It was only years later that news stories, whistleblower accounts, and police investigations led to the realisation that the software was flawed in ways that most likely led to many false allegations of fraud against sub-postmasters. While an early error rate was estimated to be less than one percent (.6%), which might seem safe, but given billions of transactions made across the postal system, this ‘low’ error rate led to many errors, almost uniformly attributed at the time to the person running the local sub-post offices.
Many factors contributed to this miscarriage of justice. These include an undue trust in IT and the technical experts; huge commercial incentives and disincentives to report the problems; government pressure to move ahead, despite questionable software, and support ICL; a culture of complicity in the Post Office; and a class divide between, on the one hand, top management and the courts within the Post Office, and on the other hand, their local sub-postmasters. This class divide made it difficult for the pleas of sub-postmasters to be seriously pursued.
Also, the scandal began to unfold in an era without social media. Each sub-postmaster accused was told by investigators that “he or she was the only one reporting problems with Horizon” (Brooks 2025: 7). They had to face these charges alone. In addition, no whistleblowers arose to support them. The police are still investigating this scandal, and a national Post Office Horizon IT Inquiry has been underway since 2020. That said, as late as 2026, it has yet to fully publish its findings.[1]
Despite many plausible explanations for the scandal, many individuals across the Post Office, the government, and the IT firm (Fujitsu, formerly ICL) must have known of, or suspected, problems with Horizon. It seems that literally hundreds of actors knew all was not right and failed to speak out (Brooks 2025). The reputational and financial damages to the Post Office would have been a major reason for hoping this would go away. Nevertheless, the failure to take it seriously was devastating. It was not until a four-part ITV drama series was aired, entitled Mr Bates vs the Post Office in 2024 that there was widespread awareness of this scandal.
Growing awareness of this scandal and the many failures to address these concerns led the Archives of IT (AIT) to organize a forum to help build a better understanding of the scandal and what actions might diminish any repeat of them. The forum, held in early in 2026, focused on the lessons learnt from the Post Office Horizon IT scandal. It was a joint event with the Worshipful Company of Information Technologists (WCIT) Ethical & Spiritual Panel.[2] The forum gave attendees access to definitive journalistic experts on the Horizon scandal and an opportunity to discuss the ethical, technical, managerial, and other practical steps the IT industry should take to prevent something similar from happening again.[3]
In this context, there were heroes who rose from the ashes of this scandal. Most notable was Alan Bates – now Sir Alan Bates – one of the leading sub-postmasters to campaign for the victims, who was Knighted in 2024, one among multiple awards and honorary degrees for his work on behalf of the sub-postmasters. For example, Sir Alan Bates, when Mr. Bates, created a website, Postofficevictims.org, to help inform other sub-postmasters that they were not alone. Many other sub-postmasters were active in supporting this campaign, such as Lee and Lisa-Marie Castleton, Mrs. Jo Hamilton, and many more are recognized in accounts of the scandal (Brooks 2025). Very few politicians seem to have taken hold of this issue, but some did, such as James Arbuthnot. Jo Hamilton was one of his constituents (Brooks 2025: 67, 86).
But there are certainly likely to be other unsung heroes who will surface through the Inquiry and future accounts of this scandal. Several leading journalists were apparent to me as I researched this scandal and listened to the Archives of IT forum. Each had led their respective news outlets on coverage of the scandal over the years. From our forum, it was clear to me that key journalists devoted considerable time over years to cover, understand, and expose the unfolding scandal.
Computer Weekly covered the scandal nearly from its inception. When the story broke, coverage was led by Tony Collins, executive editor of Computer Weekly until May 2009. Collins became well known for championing this issue. He was named Digital Journalist of the Year in the Magazine Journalism Award, for his coverage of another IT project at the NHS.[4] His coverage was followed on and further led by Bryan Glick, Editor in Chief of Computer Weekly, who spoke at the Archives of IT Forum. Computer Weekly has continued to follow the scandal and its investigation to this day.
Private Eye magazine also covered the Horizon scandal for years. Coverage was led for much of that time by Richard Brooks, one of their investigative journalists. In addition, Richard Brooks undertook a synthesis of the news coverage and interviews and went the last mile to pull together the developments into an authoritative synthesis of what happened, why, and what difference it made. He wrote an excellent book on the scandal, entitled Private Eye Post Mortem (2025). It is an informative page-turner that is a must a read for anyone with a serious interest in this scandal. [5]
Acknowledgements
My thanks to the Archives of IT for organizing this forum and to its Director, Tola Sargent, and Chair, John Carrington, for commenting on this blog.
References
Brooks, R. (2025), Private Eye Post Mortem: How the Post Office, the British Government and a Global IT Company Ruined the Lives of Thousands of Innocent People. London: Private Eye.
Dutton, W. H. (1999), Information and Communication Technologies: Visions and Realities. Oxford: MIT Press.
King, A., and Crewe, I. (2013, 2014), The Blunders of our Governments, Revised. London: One World Publications.
Peltu, M., MacKinsey, D., Shapiro, S.,and Dutton, W. H. (1999), ‘Computer Power and Human Limits’, pp. 177-196 in Dutton, W. H. (1999).
Notes
[1] Information about the Post Office Horizon IT Inquiry: https://www.postofficehorizoninquiry.org.uk/
[2] The Ethical and Spiritual Panel of the Worshipful Company of Information Technologists (WCIT) was then chaired by Richard Harvey, Professor of Computer Sciences at the University of East Anglia, who chaired the WCIT event with the Archives of IT.
[3] Highlights of the forum are available at: https://archivesit.org.uk/horizon-lessons-learnt-highlights-of-archives-ot-its-2026-forum/
[4] https://onemanandhisblog.com/2007/10/tony_collins_awardwinning_digital_journalist/
[5] It is a wonderful complement to other accounts of governmental and IT disasters, such as a book on governmental blunders by King and Crewe (2013), and a synthesis I helped write on IT disasters uncovered in an earlier generation of IT (Peltu et al 1996).