Investigators were paid cash bonuses for the convictions of 736 subpostmasters for fraud, theft and false accounting, new testimony has revealed as a miniseries about the British Post Office scandal reignites national outrage over the destruction caused by a faulty IT system.

The scandal – which began in 1999 after the British Post Office switched on Horizon, a back-end post office administrative and accounting system that was also originally intended to manage payment of national social benefits – saw 736 subpostmasters fined, jailed, or ruined after they reported balancing errors after the new system was implemented.

Rather than admitting the system could be flawed, those financial inconsistencies were used as evidence of systematic malfeasance by the subpostmasters – private franchisors running local shops equivalent to Australia Post’s licensed post offices (LPOs) – and from 2000 supported a flood of prosecutions as the Post Office pursued criminal charges.

The financial, reputational, and emotional burden of the process destroyed livelihoods and families, damaged the standing of otherwise well-regarded community members, pushed many into bankruptcy, and led to at least four suicides.

It was only after a 2009 Computer Weekly story exposed issues with the £1.5 billion Horizon system – which was awarded to Fujitsu subsidiary ICL Pathway Limited in 1996 – that the tide turned, with the treatment of the subpostmasters and subpostmistresses reaching national prominence even as Horizon continued to be rolled out across what would ultimately be around 18,000 Post Office branches.

Those revelations set off a decade-long battle spearheaded by former subpostmaster Alan Bates, who as founder of advocacy group the Justice for Subpostmasters Alliance (JFSA) catalysed the push for national recognition of the travesty of justice that had not only destroyed hundreds of lives, but exposed the culture in which Post Office CEO Paula Vennells repeatedly refused to admit the software was flawed.

Although 2013 and 2015 reports by independent firm Second Sight identified a range of issues with the Horizon system and Post Office governance, the Post Office – which terminated Second Sight’s contract before it could look into the JFSA’s claims – protested the system’s integrity until 2019, when a JFSA-backed class action led the High Court to exonerate 555 claimants and order payment of £58 million in compensation.

Blind faith in technology

Despite governments’ massive investments in bespoke IT systems over the years, the Post Office debacle echoes Australia’s experience with the likes of Queensland’s faulty seatbelt camera, the $1.2 billion disaster that was IBM’s Queensland Health payroll system, and the “crude and cruel” Robodebt scheme, which proved similarly destructive to victims who were hectored into paying wrongly calculated debts.

These and other tech-driven government IT disasters are inevitably complex, drawn out, and socially destructive as mistakes are compounded, evidence ignored, and victims forced to fight the obstinance of the institutions they served with good intentions.

The Post Office scandal, for its part, has taken on new life after a four-part TV series, called Mr Bates vs the Post Office, drew almost 10 million viewers – nearly 15 per cent of the country’s population – even as the formal government inquiry into the scandal resumed a series of public hearings that began in February 2022 and are scheduled to run through the middle of this year.

Despite the government now managing three compensation schemes, many victims have yet to receive their settlements – including many who died before being exonerated – and just 93 convictions had been overturned by the end of 2022, leading Prime Minister Rishi Sunak to promise the exoneration of the remainder.

The revival of interest in the scandal has also driven Vennells, whose tenure from 2012 to 2019 included years of stubborn resistance to the investigation, to announce that she will return her controversial CBE award amidst statements that she is “truly sorry for the devastation caused” by the subpostmasters “being wrongly accused and wrongly prosecuted as a result of the Horizon system.”

Post Office has asked the British government for $480 million (£252 million) to update Horizon, which still runs the company’s branches, while the Metropolitan Police this month opened a second criminal investigation into potential fraud offences committed during the scandal.

The revelations are set to continue: available for streaming online, the hundreds of hours of Post Office Horizon IT Inquiry hearings have been split into seven phases, with the current fourth phase – which kicked off on 12 January – focused on the creation of Horizon- related policy, audits and investigations into the subpostmasters’ alleged actions, the civil and criminal proceedings against them, and the knowledge of and responsibility for failures in investigation and disclosure.

Former Fujitsu project managers, software developers will be put on the stand in coming days, as will former Post Office investigators who were tasked with collecting evidence to support action against subpostmasters including Peter Holmes, William Quarm, Alan McLaughlin and Maureen McKelvey.

And with the year’s first day of evidence already revealing that investigators were given cash bonuses for each conviction – a perverse incentive that reveals just how strongly the system was stacked against the subpostmasters – future revelations are sure to be enlightening, controversial, and painful for all touched by the UK’s most protracted miscarriage of justice.