The Post Office has appointed a specialist investigator to review the integrity of current Horizon system data and the processes used to identify discrepancies.
This follows a report by the Post Office scandal public inquiry, published in September 2024, which raised concerns about the current version of the controversial system.
Investigation firm Kroll will review the latest version of the system, which is at the heart of the Post Office scandal, which saw thousands of subpostmasters wrongly blamed and some imprisoned for account shortfalls caused by computer errors.
A Post Office spokesperson said: “Post Office is carrying out a review of the current version of Horizon. This includes assessments of the integrity of the data in Horizon and a review of Post Office’s discrepancy identification and resolution process.”
“It comes in response to feedback from postmasters, including evidence heard at the public inquiry, highlighting concerns about the current Horizon system. Postmasters, and groups representing them, have been involved in the process, including providing input to the terms of reference for the review.”
The third-party review of Horizon was revealed in November, during the Post Office scandal public inquiry. When giving evidence, Lorna Gratton, the civil servant who sits as a non-executive director of the Post Office on behalf of the government, said there had been a discussion over the current reliability of the Horizon system.
In relation to the discrepancies that subpostmasters continue to experience when using the Horizon system, she told the inquiry: “The Post Office executive team are in the process of appointing an independent third-party review of Horizon and its robustness.”
Missing transactions
The survey, published by the public inquiry in September 2024, revealed that 57% of current subpostmasters have experienced unexplained shortfalls, including 19% reporting unexplained transactions and 14% having had transactions go missing.
Two-thirds of the subpostmasters surveyed (59%) said they were experiencing such issues at least once a month, and 69% said they have experienced an unexplained discrepancy on the Horizon system since January 2020.
Worryingly, three-quarters said they have used their own branch money to cover discrepancies or resolved the issue themselves. The survey also found that nearly half (48%) were dissatisfied with how the discrepancies were resolved, compared with the 19% who were satisfied.
Fujitsu’s contract to provide and support Horizon is scheduled to end in March 2026, and the Post Office is currently in the process of migrating all Horizon data from Fujitsu systems to its own, pending approval by the Metropolitan Police.
What happens then is still uncertain, and there have been suggestions from sources that the Post Office plans to use a combination of existing Horizon functionality, in-house software and off-the-shelf platforms for its next in-branch IT system, according to a source close to the project.
Computer Weekly first exposed the scandal in 2009, revealing the stories of seven subpostmasters and the problems they suffered due to Horizon accounting software, which led to the most widespread miscarriage of justice in British history (see below timeline of Computer Weekly articles about the scandal since 2009).
