The Fujitsu Horizon system continues to generate unusual figures in branch accounts that the Post Office cannot explain, and millions of pounds have been written off.
As an independent report is published into the system at the center of the Post Office scandal, Computer Weekly reveals that the system is in chaos.
According to a Freedom of Information request from the Post Office, subpostmasters identified more than 16,000 discrepancies in the past two years, including both account deficits and surpluses.
The taxpayer-owned business wrote off £11.6m in unidentified deficits recorded on the horizon system as losses in its latest financial results for 2023/24. In the previous financial year, it wrote off £10.4m for the same reason.
These are defects where the post office cannot identify the cause.
Figures from 11,500 branches reveal that the Post Office’s latest figures report 6,137 shortages worth more than £17m. In the previous financial year there were 5,812, worth around £19m.
The main account surplus was also reported. In 2022/23, subpostmasters called out some 2,239 account surpluses worth more than £22m. The latest figures show 2,085 surpluses totalling £17.6m.
One source said: “The Post Office doesn’t know if the discrepancies are real or not.
“The Post Office has a very poor record of keeping up with the times when it hasn’t been done well by subpostmasters. The discrepancies or inconsistencies have not been caught up in order to be good for years and have resulted in millions of pounds of tune that will either be written off using taxpayers’ money or paid for by Fujitsu. It is unknown which I believe is the former.
The Post Office said: “Like any retail business, discrepancies can and do sometimes occur in branches. If a loss was caused by an error, mistake or defect in the Horizon system, we do not seek to recover the loss from the sub-postmaster. It is important to emphasize that if the discrepancy review process is unable to determine a resolution, then we will write to that effect.”
Before 2019, sub-postmasters were forced to make good on account shortfalls that could not be explained or in many cases faced suspension or prosecution.
Thousands of subpostmasters were blamed for accounting deficits caused by errors in the Horizon computer system they used in their branches. About 900 were convicted of financial crimes based on evidence of the flawed system, and many are serving prison sentences. Many more lives were destroyed after subpostmasters were forced to pay back unexplained deficits.
If the post office was still chasing unexplained shortages, we would be in a real mess – half of the country’s branches would be closed
Richard Trinder, Sub-Postmaster
Richard Trinder, sub-postmaster of three branches in Yorkshire and Derbyshire, and a member of the Postmaster’s Voice campaign group, said the figures filled him with “absolutely no confidence”.
“If the Post Office was still chasing unexplained shortfalls, we’d be in a real mess – half the branches in the country would be closed,” he told Computer Weekly. “Luckily, they don’t hear the shortfalls while we’re sitting downtown and making phone calls.”
He said there could only be three reasons for the unexplained shortages: “Either the horizon is faulty, there was insufficient training, or people are stealing.”
A September 2024 survey by the Public Inquiry raised concerns about the current version of the controversial system, finding that 57% of current sub-postmasters had experienced unexplained deficiencies.
Of those surveyed, almost all (92%) had encountered a problem with their Horizon IT system in the 12 months prior to the survey, with the most common problems being screen freezes and lost connectivity.
Three-quarters said they had used their affiliate money to cover the discrepancies or resolved the issue themselves.
At a public inquiry hearing last November, Fujitsu Europe boss Paul Patterson admitted that there were bugs and errors in the Horizon software, but said blaming the entire issue on the application was the result of a too “narrow” definition of Horizon. He said that a number of things could cause the screen to freeze, and connectivity is provided by other suppliers.
He also said that systems that connect to the horizon, such as Polsap, the post office’s SAP platform, should also be checked when problems arise.
The results of an independent inquiry are imminent in the current system on the horizon. The inquiry was launched in November 2024 by Lorna Gratton, a civil servant who sits on behalf of the government as the Post Office Director, giving evidence at the public inquiry hearing into the Post Office scandal.
The Post Office said it will include a data integrity assessment on the horizon and a review of the Post Office’s non-compliance identification and resolution process.
Computer Week revealed that the review is being conducted by investigative firm Kroll, and the results will be available in the fall.
Regardless of the outcome, the Horizon system is set to remain in place for years to come, although the government has confirmed that the system will be replaced.
According to a public procurement announcement in May, the Post Office will eventually replace the Horizon with a shelf-free alternative, but the current system could remain in place until 2033.
The Post Office is also looking for a new supplier to support Horizon when the current Fujitsu contract expires next March. In total, the bids are worth £492m.
The Post Office scandal was first exposed by Computer Weekly in 2009, revealing the stories of seven subpostmasters and the problems they suffered due to Horizon accounting software, which resulted in the most widespread miscarriage of justice in British history ( See Computer Weekly article on the scandal from 2009 below ).
