THE new ITV drama about the Post Office Horizon IT scandal is an incredibly important vehicle for getting the story of what is increasingly recognised as one of the greatest miscarriages of justice in British history into public consciousness.

However, viewers might find themselves with one looming unanswered question as they watch: how could this persist, at such a scale, for so long? How could hundreds of people face wrongful termination of their employment contracts, loss of their businesses, bankruptcy and often criminal prosecution at the hands of the same organisation for over a decade, with no one seeming to pay any attention?

The four-part series focuses on a handful of sub-postmasters who defiantly spoke out against the injustices they faced, and who were key players in bringing this scandal to light. Chief among them is Alan Bates, a sub-postmaster from North Wales who established the Justice for Sub-postmasters Alliance and has worked tirelessly on behalf of victims of the Horizon scandal. The efforts of Bates and others have been invaluable – but they are a tiny subset of the overall victims.

Today, we know the Post Office wrongly prosecuted 736 sub-postmasters for theft, false accounting and related charges because of technical faults in the Horizon IT system, and these accusations persisted for 16 years – from 1999 to 2015. That is an average of more than one person charged per week.

By and large, most sub-postmaster victims did not speak out about the injustice they faced. Some took years to come forward, and many still prefer to remain anonymous. As depicted in the drama, the first journalist to help break the story, who was from Computer Weekly, was only able to identify and vet seven victims for her story – and it was published ten years after the Post Office began falsely accusing sub-postmasters of various crimes. So where were the other victims?

Based on a detailed analysis of hundreds of transcripts from the public inquiry and interviews with sub-postmasters across the UK, our ongoing research has enabled us to identify the four main barriers that the victims of this scandal faced when it came to speaking out.

Understanding these barriers can help us understand, more broadly, why miscarriages of justice often take a long time to surface, especially when they happen at the hands of an employer – and even more so in contexts like the Horizon scandal, where people were quick to believe the technology and blame the user.

Sub-postmasters told they were the ‘only ones’

Viewers of the ITV drama will see that accused sub-postmasters were repeatedly told they were the “only one” having problems with the Horizon system, even when cases like theirs were going on all over the country. We found similar accounts time and again within the public inquiry witness statements, with one witness,

Katherine McAlerney, representing the experiences of many when she said: “I was told during my interview that I was the only one who had a problem like this with the system.”

Another sub-postmaster, Margery Lorraine Williams, recalled:

I confirmed that I had not done anything wrong and asked again about issues with the Horizon system. I was led to believe at this meeting that I was the only sub-postmaster who was having problems with shortfalls. It made me feel stupid that I was the only person who had these issues.

However, the ITV drama quickly moves past this period, and we see the sub-postmasters coming together and finding out about each other’s similar situations. While this is a key turning point in bringing this injustice to light, in reality most of the sub-postmasters suffered for years believing what they had been told – that they were the only one – before becoming aware of any other victims.

In her witness statement, McAlerney said: “I believed firmly that I was the only one until about four years later, when I saw an article about the Horizon system and I thought: ‘Oh my god, that is what happened to me.’”

Another key person whose story we see in the TV drama, Hughie Noel Thomas, was sentenced to nine months in prison in November 2006, based on faulty information from Horizon. A few scenes after we are introduced to Thomas in the drama, he is shown meeting with another key sub-postmaster, Jo Hamilton. In fact, this meeting occurred nearly three years after his sentencing.

Thomas has written a memoir in which he reflects on his feeling of isolation over those three years, and how it discouraged him from speaking out.

He wrote: "With no mention anywhere else that any other sub-postmaster had been implicated in the same way as I had been, it all seemed completely hopeless. I was all on my own, in a post-prison hell. And it was a terribly lonely place to be, believe you me."

When we interviewed Thomas near his home in Anglesey, North Wales, about this “in-between” period, he said: “After I went to prison, I was in cuckoo land for three years. I was basically silent about everything until I found the others.” In his memoir, he refers to finding out about other victims as “manna from heaven”.

Another victim we interviewed, Janet Skinner – who pleaded guilty to false accounting and was sent to jail for nine months – told us that she felt similarly isolated, and was also reluctant to speak out publicly about the injustice. Instead, she “tried to bury it” because she too was led to believe she was “the only person who was having any kind of issues with the system”.

Being told they were the only one not only discouraged victims from speaking out, it also planted a seed of self-doubt in many of their minds. As Hamilton, a sub-postmaster from a village in Hampshire, told the public inquiry:

I began to feel like I was going mad and that it was entirely my fault … When he said I was the only one, that’s how I did feel … I thought: Oh God, I must be – you know, I just thought it was me.

This cycle of isolation and self-doubt helps explain why most did not attempt to find other possible victims or try to speak out publicly about the injustice – which contributed to the scandal persisting for so long.

‘Spat on, shouted at and shunned’

There are countless examples of victims of the Horizon IT Scandal being stigmatised in and by their local community. While the drama focuses on the heartwarming story of Hamilton, who received an inordinate amount of support from her local community, most sub-postmasters were not so lucky. In fact, they had quite the opposite experience.

Our analyses of the public inquiry statements reveal the local stigmatisation and shame that many felt. There are vivid accounts of sub-postmasters being spat on, shouted at and shunned. As sub-postmaster Nicola Arch, who had worked for the Post Office since 1993, told the inquiry:

In the village, I couldn’t walk through it without people [thinking]: ‘This is the lady who stole from the pensioners.’ It was all in the local papers. I couldn’t go in the supermarket – the whole place would go silent. Village life was so … almost incestuous. Everyone knew everybody. It was a living nightmare to the point where I refused to leave the house … I stayed indoors and never even went out to the shop for 19 months.

Skinner, one of more than 230 sub-postmasters who were wrongly jailed, told the inquiry: “People automatically assume that you are a thief … You have a stigma. It’s people talking about you and pointing the finger at you. ‘Oh, that’s that woman who nicked all the money from the Post Office. Do you remember?’ I’ve heard that so many times.”

In his memoir, Thomas described how it felt to lose his standing in his community. “I felt this immense sense of shame … Shame for myself, shame for my family, and shame for my community to have been drawn into such a scandal.”

We have also collected and analysed local news reports on the early accusations. Common themes include describing the allegations as “stealing from pensioners” or “having their hand in the till”, and the sub-postmasters frequently being labelled as criminals and thieves and exhibiting a “fall from grace” – even when they were not prosecuted.

This sense of shame is just the tip of the iceberg in terms of the negative mental health effects that sub-postmasters experienced from being wrongfully accused. A 2023 study found no difference in the severity of mental health symptoms between the sub-postmasters convicted of criminal offences and those who were investigated, prosecuted or pursued in a civil court. Those who experienced a wrongful accusation had similar negative mental health outcomes as those who were wrongfully convicted.

Our research leads us to believe these feelings of shame and experiences of stigmatisation discouraged people from speaking out about the injustice.

Victims were unable to defend themselves

But what if someone did want to speak out and fight back? Those who did faced an impossible task.

Imagine that, tomorrow morning, you walk into work and are called into your line-manager’s office. They accuse you of something and tell you to gather your personal items as you are being sacked. You try to reassure them you’ve done nothing wrong, and you know that if you can access some files on your computer, you can clear it all up. But when you go to your desk, you see that your computer is gone, along with your access to all your IT systems, emails, documents and archived electronic files.

This is the nightmare reality that sub-postmasters who were accused of theft and false accounting often faced. The Horizon point-of-sale IT system provided them with a very limited paper trail to cross-check their transactions – and when they were investigated, everything was seized from them (even their paperwork) with no notice. As one victim, Keith Macaldowie, recalled during the inquiry:

They closed the office when they suspended me, so I couldn’t gain access. They took all of the keys off me for the post office – the safe and the till – and I was locked out of Horizon.

Those who tried to fight the false accusations had a hard time convincing others that Horizon was at fault. As Lee Castleton, a former sub-postmaster from Bridlington who is profiled in the ITV drama, told us in an interview:

I went to court and lost epically. I couldn’t have done any more. I’d been presented with a problem, a problem that I couldn’t climb over [and] couldn’t get my head around. I couldn’t make other people understand what I was trying to show them.

Castleton was bankrupted by his legal ordeal. Because sub-postmasters did not have the information to prove their innocence, many ended up taking plea bargains. One who prefers to remain anonymous told us he took a plea bargain because he “couldn’t prove that I didn’t do it”. After pleading guilty, he said he wasn’t sure even his parents believed he was innocent until his conviction was overturned. Like so many others, he waited decades for his conviction to be overturned. Many more are still waiting.

In May 2021, a BBC news report revealed that former sub-postmaster Parmod Kalia hid his conviction from his closest family members for 20 years. He only revealed to them what happened when his conviction was overturned.

Overall, we found the lack of access to information that could prove the sub-postmasters’ innocence discouraged them from trying to speak out. This finding is particularly pertinent for workplace disputes, especially in the digital age when someone’s communications are usually all electronic and are technically owned by their employer. It is a frightening reality that if you are suspected of something at work, you can immediately lose access to any information that will prove your innocence.

‘The Queen’s business’

At the time these false accusations were taking place, the Post Office was seen by many as “the nation’s most trusted brand”. The high reputation it had in society further encouraged sub-postmasters to think no one would believe them if they tried to fight the injustices they faced. As one of the victims, Nicola Arch, told us:

Working for the Post Office, it was the Queen’s business. It was very respected, very highly regarded. The Queen acknowledges the Post Office — her face is on the stamps. In that era, everyone believed that it was a very prestigious company to work for, very respected … Everyone thought the Post Office could never be wrong.

Skinner recalled a similar experience when we interviewed her. “I think because of the reputation of the Post Office, people believed them over you – even though you were telling the truth … It was a case of: ‘Well, she must have taken the money, or else why would she have gone to prison?’ So [my response] was more buried than fighting against anything.”

It wasn’t only the general public who had faith in the Post Office. Among both its management and audit team at the time – which we know much more about now through the public inquiry – there was a hierarchical culture in which criticism was not welcomed.

Despite individual appeals by sub-postmasters, Post Office managers did not challenge the leadership or organisation, and apparently believed their systems, including Horizon, were infallible. Over and over again, the Post Office made public statements about Horizon being “robust”.

In a 2021 Court of Appeal decision that cleared the names of dozens of former sub-postmasters, Lord Justice Holroyde said the Post Office knew there were serious issues with the system, yet “consistently asserted that Horizon was robust and reliable” and “effectively steamrolled over any sub-postmaster who sought to challenge its accuracy”.

In interactions with sub-postmasters, the Post Office auditors emphasised that the computer could not be wrong, as shown in the following account from Arch’s witness statement to the inquiry:

[The auditor said:] ‘You popped it in your purse.’ I said: ‘No, I didn’t.’ I told him the daily totals were right and I had evidence to show that, but I couldn’t access it. And he replied that he was not interested in what I said as the computer was the most hi-tech equipment you could wish for, and no one else had had any problems with it.

The myth of ‘infallible systems’

The lack of willingness on the part of the Post Office to even entertain the idea that its IT systems might have a problem discouraged sub-postmasters from trying to resolve the issue with the Post Office directly. It also fuelled their self-doubt about whether this “perfect” system really could have any bugs in it.

This last factor is particularly pertinent for disputes around technology, in which people can easily fall prey to what researchers call “automation bias”, a psychological bias in which people readily discount information that does not conform to what technology advises or has determined.

When injustices comes to light, often years after harm has occurred, we often hear people ask: ‘If this was going on, why didn’t they tell someone? Why are they only saying this now?’

In examining this case, we have found there are numerous legitimate reasons why victims don’t speak up – especially when they are intentionally isolated, experience self-doubt, feel ashamed about what has happened, and are not given access to the vital information they need to prove their innocence against a powerful perpetrator.

It all seems so obvious in hindsight. Sub-postmasters were highly vetted and highly skilled people. Post Office employees have given evidence confirming that sub-postmasters were subject to “good character checks”. Statistically, such a high percentage of them being criminals was very unlikely. This alone should have raised concerns about these accusations, both inside and outside the Post Office.

But Post Office management falsely believed their technological systems were infallible, and dug their heels in at any opportunity to recognise this injustice for what it was.

At the end of the day, this is not a scandal about technological failing. It is a scandal about the gross failure of management to stand up for the human beings who had dedicated so many years of their lives working for ‘the Queen’s business’.


  • Grace Augustine, Associate Professor in Business & Society, University of Bath
  • Jan Lodge, Assistant Professor, Department of Business-Society Management, Rotterdam School of Management
  • Mislav Radic, Assistant Professor, Department of Social and Political Sciences, Bocconi University