British justice is a splendidly odd animal. Its miscarriage is one of those wonders of institutional repetition. When textbooks are written on the subject, one will feature prominently. On April 23 this year, the convictions of 39 former sub-postmasters were quashed by the criminal division of the Court of Appeal. They had been accused, and convicted, for theft and dishonesty after the UK Post Office installed the wonky wonder of the Horizon IT system.

There were figures such as Seema Misra, convicted for stealing £74,000 in cash from the Post Office branch under her stewardship in West Byfleet in 2010. At the time, the press delighted in calling her the “pregnant thief.” Her husband was assaulted by locals. Della Robinson, who ran the Dukinfield, Greater Manchester Post Office, could not account for £17,000 by 2012. She was suspended, reported to the police, and faced a community service sentence.

The reason for their convictions lay in the accounting nightmare produced by the Horizon system. It had ominous beginnings, growing up from a contract between the computer company ICL, the Post Office, and the Benefits Agency, all part of what were termed private finance initiatives (PFI). Developed by Japanese company Fujitsu, Horizon featured a swipe card system for paying pensions and benefits via the counters of Post Office branches. The venture proved calamitous, ailed by chronic mismanagement, weaknesses in the technology, and general human incompetence. The cost of that endeavour to the British taxpayer: £700 million.

Refusing to wipe the slate clean, the Post Office beefed up the Horizon project, using it to convert accounting done through paper format into an electronic system. Over time, this made it the largest IT contract in Europe not connected with the military. But the stench refused to go away. “Serious doubts over the reliability of the software remained,” warned the Post Office board of directors in their minutes in September 1999.

Glitches duly mounted. Variations in revenue in some branches were noted. Two months after Horizon began operating, the Post Office branch in Craig-y-Don in Wales showed up a “variance” totaling £6,000. In time, these proliferated. In some cases, sub-postmasters, seeing these errors as not occasioned by computer error but their own, sought to cover revenue discrepancies with their own resources. Their contracts did mention that shortfalls be covered in instances of “carelessness or error.”

Between 2000 and 2014, the Post Office, with witch-hunting zeal, prosecuted a stunning 736 sub-postmasters, seeking convictions for false accounting and theft. Many were financially ruined. A number took to addiction, suffered ill-health and premature death. The sheer number facing charges raised an obvious question: how could there have been so many copy-cat crimes perpetrated by supposedly upstanding workers? (The Post Office itself admitted to investing time identifying and recruiting appropriate candidates.) The more troubling, and logical reason: the continuing, near manic refusal to acknowledge the gremlins in the Horizon system.

The sub-postmasters fought back. In December 2019, the Post Office agreed to settle with 555 claimants, accepting that it had previously erred in its “dealings with a number of postmasters,” agreeing to pay £58m in damages, with claimants receiving a £12 million share after legal fees.

Battle that year was also waged in the High Court through several trials. The Post Office, remarkably, attempted to tar the presiding judge Sir Peter Fraser in one case with the brush of bias, suggesting he step down. The failed effort to recuse him had arisen because of a previous ruling that over 500 sub-postmasters had been wrongly held responsible for Horizon’s accounting bungles. In another of Justice Fraser’s judgments handed down in December 2019, the Post Office was accused of showing “simple institutional obstinacy or refusal” in considering “any possible alternatives to their view of Horizon, which was maintained regardless of the weight of factual evidence to the contrary.” Reality was ignored. “It amounts to the 21st century equivalent of maintaining that the earth is flat.”

The Criminal Cases Review Commission (CCRC) proceeded to refer 42 sub-postmaster cases to the Court of Appeal. The judges were charged with considering whether the prosecutions had been an abuse of court process and whether the convictions were unsafe. The salient consideration was whether the Horizon accounting system, already damned by Fraser, was reliable or not.

To the last, the Post Office, rather than conceding in full error, fought. It did concede that 39 of the 42 former sub-postmasters “did not or could not have a fair trial.” But in 35 of those 39 cases, it objected to the claim that the prosecutions were “an affront to the public conscience.”

In the criminal division of the Court of Appeal, Lord Justice Holroyde and his fellow judges found the “failures of investigation and disclosure were in our judgment so egregious as to make the prosecution of any of the ‘Horizon cases’ an affront to the conscience of the court.” The Post Office had effectively reversed the burden of proof by firstly assuming that the Horizon system was reliable and placing the onus upon the sub-postmasters to show why shortfalls had been registered. “Denied any disclosure of material capable of undermining the prosecution case, defendants were inevitably unable to discharge that improper burden.” Their prosecutions, convictions, and sentences were pursued “on the basis that the Horizon data must be correct, and cash must therefore be missing, when in fact there could be no confidence as to that foundation.”

The snarling ugliness of conduct by the Post Office was laid bare. It refused to comply with its own obligations when prosecuting the sub-postmasters using Horizon data. It doggedly insisted that the sub-postmasters “make good all losses and could lose their employment if they did not do so.” This was all done despite the selection of those very same individuals as trustworthy occupants of their positions. The Post Office also dismissed claims that the shortfalls had arisen because of “an error or bug in the system.” Internal documentation dealing with the explanation by one sub-postmaster that a system error had occurred was contemptuously swatted as “jumping on the Horizon bandwagon.”

Of the 42 original appellants, only three – Wendy Cousins, Stanley Fell and Neelam Hussain – failed to achieve their aim. Their convictions were found to be safe, as “the reliability of Horizon data was not essential to the prosecution case.” For the rest, a grotesque, wearing chapter of British injustice had been reversed. An unquestioning faith and dogma, alloyed with some venality, had been repudiated. Sadly, the Post Office executives, board members, and those at Fujitsu, remain at large, ready for the next erring.