The Post Office case is damning, but do not blame ‘computer error’ – it is very much the fault of human error of Post Office managers

23rd April 2021

There are few, if any, criminal appeal judgments as damning as today’s appeal judgment on the post office cases.

This is an appeal judgment that will (or should) sound through the generations, as a detailed description of how the criminal justice system can go wrong.



It would be an error to dismiss it as just a grand example of ‘the computer says no’.

Computers, like any automatic processes, will be prone to faults.

The problem was not so much the Horizon software but a sequence of horrible, deliberate decisions made by human beings – about whether to bring prosecutions, to contest civil cases, and to avoid the disclosure of relevant documents.

Every single manager involved in these prosecutions and in opposing appeals are far more culpable than any of the poor defendants.

Yet, unlike the defendants, the Post Office managers are not (generally) named in this judgment: they have their gongs and their pensions and their self-serving supposed exculpations of ‘lessons learned’.

So damning is this judgment that, no doubt, every person reading it will have a view on which of their legal and political opinions will be affirmed by the judgment.

For this blog, the damning Post Office judgment affirms that private prosecutions are generally a bad thing – whether they are brought by the Post Office or anyone else.

Some organisations – and individuals – enjoy the swagger and the bluster of being able to bring (and threaten) cases aimed at criminalising and penalising others.

But as the noted jurist Benjamin Parker averred: with great power comes great responsibility.

And the power to criminalise and penalise others is one of greatest powers and responsibilities of all.


Lawyers often boast of being ‘fearless’.

Prosecutions should be – genuinely – fearless: but being fearless including being free of the fear of not proceeding with the prosecution because of the reason of embarrassment.

For, as the damning Post Office judgment shows, it was the fear of embarrassment that meant that things were not said and disclosed that should have been said and disclosed.

The damning Post Office judgment also shows what will happen when the power and the urge to prosecute is free from any checks and balances.

It shows what will happen when defendants do not get the materials and the advice that they need so as to be properly defended.

Yes: the appeal points to the dangers of automation and computerisation – but the appeal points harder at the dangers where managers and other decision-makers hide behind automation and computerisation.

And the delay in this appeal judgment – ten or so years after the miscarriages of justice – also shows the inefficiency of a criminal justice system that can often be so quick to impose criminal liability in putting right things when they go wrong.

Nobody – other than the defendants – come out of this judgment well.

Not least the criminal justice system itself.


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25 thoughts on “The Post Office case is damning, but do not blame ‘computer error’ – it is very much the fault of human error of Post Office managers”

  1. This is a horrible case. It is also familiar. Readers of Private Eye have been seeing elements of this for years. All the time the behaviour of the Post Office management has been awful. Even the high level apologies proffered now ring hollowly of reluctance to compensate the victims of this injustice.

    More seriously, whatever rules of evidence there may be do not seem to have applied here. Was there enough disclosure? Was there, in the constant lie told to the postmasters that ‘nobody else has a problem’ a case of institutional corruption and perjury on a large scale? And were the individuals thus persecuted just individuals, without collective power until they discovered each other, who should have been covered by a duty of care from the PO, not a campaign of abuse.

    Listen to the from on Radio 4 to get the history. Its worth the time.

    1. I gathered from R4 that the PO actually lied to individuals, telling them in response to questions from those individuals, that, no, no-one else in the country was being investigated! Pure evil. Also it should have been so obvious to investigators how very unlikely it was that the Man in the Clapham Sub-Post Office would suddenly turn his or her hand to stealing thousands of pounds.

  2. DAG notes that few individuals involved in the pernicious and immoral if not illegal decisions that led to the prosecutions are named. I take from this that they are not likely to face any consequences.

    Is it not a theme of this blog, in its various subjects, that individual responsibility in the public or corporate realms simply does not function as many of us think it should? This seems to have spread everywhere, like a disease. (In contrast, say, the criminal law, or immigration law, are swift to take action against certain classes of individuals.) DAG often refers to the public’s indifference to poor behavior in government. Our indifference seems to go far beyond politics.

  3. Thanks David – this point should get wider audience than it will with me screaming at the radio/TV. The problem is not with the ‘computer system’ at all – I can almost guarantee it was badly specified and not by the people who would use it, the specifications were the misunderstood, the end product was rushed, the project ran late, testing wasn’t sufficiently robust, etc.

    The real crime is that everyone in the Post Office management hierarchy would (or should) have know that and not one of the lily-livered idiots spoke up to defend the SPMs. Real justice now needs to be done if only as a lesson to others who may try the same.

  4. David, can we please have this followed up so we can see the extent to which the cullprits are identified and pointed out?

    A downward glance a crumb of humble pie and a few words of horribly foreshortened apology before swishing off to the club will really not do. Time for examples to be set.

    I would hate the outcomes to be pushed out of mind to the middling pages.

  5. What broke me today was reading of the 3 families (Wilson, O’Connell, Holmes) who were hearing their loved ones convictions quashed posthumously; their family members had gone to their graves with their innocence in question.

    Add to that a number of other people, identified in the Private Eye report in April 2020, who had taken their own lives whilst under pressure from the Post Office.

    This strategy that the Post Office pursued was heartless at its core.

    I wonder if the Post Office board members involved in this scandal can read the stories of these families with an ounce of compassion.

    I suspect not.

  6. There are so many shocking aspects to this debacle that it is difficult to know where to start.

    It certainly wasn’t a case of a “few errors”, or a few “bad apples”. It was systematic and endemic, and carried on for years. The lives of many good and honest people were ruined, for amounts that in many cases may never have been “missing” in the first place.

    There is much more at

    1. I can’t help thinking that we will need to dig much deeper on this. Like many occasions when things go wrong, there is not one error by one person here, but rather a concatenation of errors by different people over a long period of time. And perhaps worse a false sense of confidence and incuriosity about potential problems. The sort of group-think you sometimes see in the police, for example.

      As I understand it, the Horizon system was developed in the 1990s under a PFI contract by ICL (80% owned by Fujitsu since 1990) for the Benefits Agency and Post Office Counters, to replace hardcopy benefits books with smartcards. It was piloted from 1995. Some 25 years plus on, we are talking about very old technology now (just remember if you can the computers you were using then) and I bet it was not cutting edge even then.

      The context was one of privatisation (the earlier separation and flotation of BT, sale of Girobank, and moves towards separation of Parcelforce) under the 1990s Conservative government.

      Things remained much the same under the post-1997 New Labour government. This is when the Horizon system was rolled out by the Post Office, although after four years of testing and approaching £1 billion of cost (again, about 20 some years ago, when a billion was real money) the Benefits Agency withdrew from the project in 1999. Did Horizon not work as they hoped, or did a better and lower cost option emerge?

      Nonetheless, the Post Office introduced the Horizon system anyway from 2000. Is this sunk costs in action? They needed a computer system, and they’ve spent so much time and treasure on creating this one that they have to adopt it? Despite four years of testing, persistent errors came to light almost immediately after it was rolled out. Did it ever work 100% as intended?

      Then, Royal Mail delivery was separated from the Post Office Counters in 2012, under the Con/Lib coalition government’s Postal Services Act 2011. At that time there were ideas around mutualisation of the Post Office. What ever happened to that?

      Royal Mail (without the Post Office) was privatised in 2013, although the government keeps a stake. But the Post Office is still government owned, and there has been a succession of ministers responsible for postal services back to the days of the Postmaster General. What responsibility do the politicians carry here?

      There has been much focus on the MD/CEO of the Post Office from 2012 to 2019, Paula Vennells, and no doubt she is not free of sin, not least in the institutional intransigence and failure to accept there were problems with its “robust” system. But many perhaps most of the problems arose before before the Post Office was separated from Royal Mail – under previous bosses, John Roberts (to 2003) and Adam Crozier (2003-2010) and Moya Greene (from 2010). What responsibility do they bear for introducing Horizon and continuing to use it?

      And then much blame must be directed at the conduct of the security investigation and prosecuting bodies within the Post Office itself. The head of security for most of this period was John Scott, who seems to have left the police to join the Post Office in 1993, and was head of security from 2007 until 2016 I believe, but despite that long experience he seemed to have a very peculiar attitude to fairness and disclosure in 2013. More here and

  7. Having worked in corporate IT for over 25 years this all seems very odd. Systems do go wrong. They are coded by human beings. There are logic errors and problems with software. It was often my job to find those errors, work out what had gone wrong and fix the problems. In all those years I was never told ‘Oh, this is fraud’ or
    ‘This is theft’ when we had an imbalance in the accounts. It might have been more exciting than tracking down the problem with the software but it never happened. So, it seems like a sort of criminal laziness to me.

  8. As regards known process failings, disregard for truthfulness and heartless indifference shown to victims, there are a daunting number of other similar and recent examples. My own list includes the treatment of asylum seekers by the Home Office and of some clearly vulnerable benefit claimants by the DWP.

    I’ve never understood how it’s possible for reasonably decent individuals to knowingly carry on treating other human beings appallingly, on the flimsy grounds that they do. One becomes what one does …

  9. Thank you for this piece: good points well made.

    One excuse I would never – NEVER – accept when dealing with any difficult issue is ‘the computer says …’ Having worked as a programmer in the days when that meant punching your own cards, and much, much later being responsible for the processes within a section within a large bureaucracy, I quickly learnt that people make mistakes but computers can make the mistakes bigger and harder to correct.

    I find it very hard to understand how people in the Post Office management structures could convince themselves that all these new anomalies being discovered were genuine malfeasances rather than failures of the accounting system. Maybe reading the judgement will make it clearer but I’m not holding my breath. I fear that this was simply a more visible, and more damaging example of the general principle that if a problem arises the weakest will be sacrificed in the hope that that will solve it.

  10. Thank you for your work David.

    I agree with you that private prosecutions are generally undesirable. I was astonished to discover recently that should one find themselves victim to fraud perpetrated by a corporation that you happen to have an agreement with, the police will not act regardless of the strength of the evidence provided. The police would advise you to seek your own prosecution in a civil court.

    In the case discussed, am I right to think that should a postmaster have handed the damning evidence that has come to light in court to the police, they would not have sought prosecution of the Post Office for criminality, but would have done so if it had been an individual that deceived another in the same way? I am sure I am not your only reader who misunderstands the facts of the distinctions as they stand and wonders why they do.

  11. I worked in IT for many years and back in the ’80s heard rumours of problems at the Post Office. Essentially a highly secretive and politically vicious culture. A dangerous place to work. As OGH points out the prosecutions are not a ‘computer problem’ but a management problem.

    But also a legal problem, it was lawyers who took on these prosecutions and some at least must have smelt a rat. There seems a certain deliberate intellectual incuriosity in not looking below the surface. No one apart from the accused comes out of this looking clean.

    As for the future and some prospect of ‘justice’, an ancient principle of management failure is the persecution of the innocent and the reward of the guilty. Expect some money to be thrown around but little else.

  12. Are we missing something? Was the system acquired under PFI? I think I heard that on R4, but fleetingly. If this is so what difference does it make to the contractual relationships, the PO level of understanding and the source of the fraud? Should the police be pursuing the system vendor? It doesn’t excuse the lying and it might have made it worse and more ignorant, with PO management having no clue about what the we’re doing?

  13. “The Post Office settled the civil claim brought by 555 claimants for £57.75m – amounting to £12m after legal costs” ( Surely this is also a scandal: the lawyers get three times more money than the victims

    1. It isn’t just Lawyers who took part of the “costs” it was a litigation funder Therium. In addition they settled part way through the whole set of litigation – because the post office has bottomless pockets and the claiments were about to end up owing money even if they won.

      For more about litigation fimders look here:

  14. Over 900 employees were prosecuted; this approaches 10% of the number of post offices.

    What was missed was simply this; how can it be that 10% of people who run our post offices are crooks? Of course, there can be crooks in any organisation, but doesn’t 10% seem a large number? And isn’t it wonderful that our new system has identified them?

    This is yet again an example of the “prosecutor’s fallacy” that was discussed here a few days ago.

    The fallacious thinking is obvious when Bayes’s Theorem is applied.

    What steps, if any, are taken during law courses for solicitors and barristers to ensure a basic competence in mathematical and statistical understanding?

  15. Certainly damning, but like many others who have commented, the ‘guilty’ get away scot free? Apologies are made and the losses will be repaid by the tax payer. The sub postmasters/mistresses will be reimbursed, their criminal record removed, but is that justice?

  16. There’s a great series on this issue on BBC Sounds and R4 at the moment.
    But there seems to have been little focus on the fact that it seems that each and every person who reported problems to the PO was told that they were the only one having issues. The help centre must surely have been briefed to say this as the staff working there must have quickly found that it was simply untrue.
    Who briefed them and decided that that patently untrue line should be maintained?
    But there is now, rightly, rather more focus on the role of Fujitsu as well as the PO leaders.

  17. As I understand it from other reports, the Post Office gradually discovered over the years that their computer system was not in fact infallible, which had been the premise on which all these prosecutions were founded. But rather than causing any change of tack, their response was to conceal this fact and plough on regardless. Everyone within the Post Office who was responsible for this disgraceful course of action needs to be identified by a proper investigation, and held to account for their dishonest and malicious behaviour.

  18. FYI the Private Eye podcast on this ‘Going Postal’ is also interesting. I return to the issue of PFI. Was this system supplied under PFI and what were the boundaries of the contract.? I fear that the system, including the support and debugging, was a black hole that the PO management had no access to. Where do these constant claims of ‘no-one else has a problem’ arise from? What, after all, was the underlying bug or set of faults – which have now presumably been remedied or worked-around. And, as DAG implies in today’s input, how old was the underlying code anyway?

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