In 1999 the UK government set out to automate accounting at around 14,000 Post Office branches. Fujitsu supplied a centralised computer system called Horizon, and it replaced paper records. Soon after it went in, subpostmasters began reporting shortfalls they could not explain.
On paper, nothing about their contracts had changed. Subpostmasters ran their own businesses as Post Office agents and were still held responsible for any shortfall unless they could prove otherwise. But the paper trail that once let them trace a discrepancy was gone. Many found it nearly impossible to show the losses were not their fault. When they failed, they had to cover the gap, and the Post Office treated the shortfall “as having been caused by dishonesty or at best carelessness” on their part.
For 15 years the Post Office used its own private prosecution powers, without involving the police, to bring cases against more than 700 subpostmasters for theft, fraud or false accounting. Hundreds went to prison. Others got community service or electronic monitoring, and many were left with criminal records. Analysis by Vaultinum puts the human cost at no fewer than four suicides, a woman jailed while pregnant, and countless bankruptcies.
What the courts found
The turn came in 2019, in Bates & Others v. Post Office Ltd. A group of 555 branch managers took the Post Office to the High Court and won. The court confirmed that Horizon was error-prone, which the Post Office had denied for years. The Post Office settled, and the ruling gave convicted subpostmasters the evidence they needed to appeal.
The Criminal Cases Review Commission referred cases to the Court of Appeal. In Hamilton & Others v. Post Office Ltd, 42 people, mostly subpostmasters, challenged convictions tied to financial discrepancies. The court found the prosecutions were an abuse of process and an “affront to the conscience of the court.” Thirty-nine of the appellants were fully exonerated. The BBC called it “the UK’s most widespread miscarriage of justice.”
The evidence was damaging. Subpostmasters had reported “phantom transactions” to Fujitsu, and when Royal Mail engineers visited an affected branch they saw the phantom entries themselves. Fujitsu still blamed operator error, a position Judge Fraser called “simply and entirely unsupportable.” The judgment also found that Horizon gave subpostmasters no way to dispute its figures, and that the Post Office knew of bugs and defects well past any early teething problems but did not tell everyone affected. Its stated aim in fighting claims, the judgment recorded, was to stop subpostmasters “jumping on the Horizon bashing bandwagon.” Problems with the system had been reported in Computer Weekly and raised in Parliament as early as 2009.
Compensation and accountability
By January 2024, of 983 wrongful convictions, 700 of them brought by the Post Office, just 93 had been overturned. Compensation was crawling too. Several subpostmasters died before they were paid.
What moved the government was television. ITV broadcast the drama “Mr. Bates vs. the Post Office” that January, and Prime Minister Rishi Sunak pledged new legislation to exonerate and compensate all victims. Former Post Office head Paula Vennells gave back an honour after a petition with more than a million signatures demanded it.
No Post Office or Fujitsu executive had been held accountable at that point. Police later opened Operation Olympos, run by a national team of about 100 officers working through more than 6 million documents. Between Christmas 2024 and June 2025 they identified seven suspects among more than 45 “persons of interest,” a group that includes Post Office investigators, lawyers and Fujitsu staff. Four of the seven have been interviewed under caution over alleged perverting the course of justice and perjury. Prosecutors will wait for the public inquiry’s final findings before filing charges.
Sources
Sources
- British Post Office scandal – Wikipedia
- The UK Post Office Scandal: why it is important to proceed to a Tech…
