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Post Office IT support email reveals known Horizon flaw

An email from Post Office IT support reveals a problem with the Horizon system and supporting processes that could lead to accounting errors

Technicians supporting the Post Office's Horizon IT system have revealed a known software flaw that could lead to subpostmasters submitting inaccurate accounts.

Post Office IT support sent an email to a member of the postmasters' branch of the Communications Workers Union (CWU) revealing the flaw. The email said Post Office IT support planned to fix the glitch “with a code change” in early 2016. Subpostmasters have not been warned about this flaw in the system.

Campaigners blame the Horizon computer system (see panel below) for accounting shortfalls that have led to subpostmasters being fined and even jailed. The Post Office has consistently denied this.

In November 2015 the CWU wrote to subpostmasters warning them of a problem with the system, following an incident in which thousands of pounds' worth of payments were duplicated for one subpostmaster. If undetected, this would appear as losses when the accounts are completed, which would be the responsibility of the subpostmaster.

The Post Office told Computer Weekly it had given the affected subpostmaster a “full outline” of the cause of the duplication of payments, but would not give details.

Previous instances

But in an email to another postmaster, who is also a CWU member, about the case of duplicated payments, Atos – the company that provides IT support for the Post Office – described the problem, and said it had happened before.

In the email – which Computer Weekly has seen – an Atos representative said: “This issue is caused by the user forcing log off when the post-login checks have not fully completed. We have experienced previous instances of this issue in other branches [that] have been caused in the same way (forced log off).”

The Atos employee said the problem is a process issue that would require a code change, from Horizon supplier Fujitsu, to stop it happening again across the network. The email said the code change was planned for March 2016.

“The ability for this to occur can be addressed by a code change that will avoid further instances of this across the estate,” said the email. “The code change will be included within Release 13.05 which will be developed by Fujitsu and deployed in March 2016."

What is Horizon?

In response to a Freedom of Information (FOI) request made in 2011 by the Justice for Subpostmasters Alliance (JFSA) campaign group, the Post Office explained the scope of the term "Horizon".

“This encompasses the software, both bespoke and software packages, the computer hardware and communications equipment installed in branch and the central data centres. It includes the software used to control and monitor the systems. In addition I can advise you that testing and training systems are also referred to as Horizon,” said the Post Office.

The Atos helpdesk has closed the case, but the CWU postmasters branch claimed the supplier had not investigated it properly.

Mark Baker, postmaster branch secretary at the CWU, said the explanation given by Post Office IT support could not be the right one regarding duplicated payments, and claimed it was evidence of a different flaw.

 “This subpostmaster only had one terminal and forced log-off only occurs when you try to use a terminal when already logged in to another,” he said. He added that it could not have been caused by the system logging off automatically after being unused for a while, because records show the transaction was made after the previous log-off happened.

The Atos email said: “From an IT perspective we have agreed that this can be closed as the incident is resolved. That said, we are aware of the ongoing work the Finance Service Centre (FSC) will need to do with [the subpostmaster] and we have asked this team to pick it up and I understand contact has been made.” The subpostmaster did talk to the FSC to have the duplicated transactions corrected, but has had no contact since then, said the CWU.

The Horizon dispute

The possibility of a flaw in Horizon that could cause undetected accounting errors is critical in light of the disputes between some subpostmasters and the Post Office that have been running for years. In 2009 Computer Weekly revealed the stories of subpostmasters who had received heavy fines and even jail terms for alleged false accounting – which they blamed on the system and supporting processes. The Post Office has vehemently denied this claim. (See timeline below for more about the dispute).

Computer Weekly asked the Post Office whether it was investigating the duplicated payment issue identified initially by the CWU, and whether it had contacted the union as a result. The Post Office’s head of communications, Mark Davies, said: "We look at any and all issues raised with us through our channels. Obviously if any postmaster calls our service lines with a query we look at it, as you'd expect. The issue has been raised with us through our normal channels (postmaster contact to service centre) and answered through those channels.”

Computer Weekly also asked the Post Office several questions about the contents of the Atos email to understand if the two problems were the same or separate. The Post Office said: “We will not be commenting on this issue any further other than to say that the Post Office takes its responsibilities towards its postmasters extremely seriously and wholeheartedly rejects any suggestion to the contrary."

In response to previous Computer Weekly articles, the Post Office recently said: “It remains the case that more than three years of investigations have not identified any transaction caused by a technical fault in Horizon which resulted in a postmaster wrongly being held responsible for a loss.”

There have been allegations that the Post Office has not properly investigated problems in the past. An independent report into the Horizon system and individual subpostmaster cases by forensic investigation company Second Sight, which was commissioned by the Post Office and published in April 2015, said the Post Office was too quick to go to court in some cases of subpostmaster account shortfalls.

“As a result of our investigations we have established that Post Office's investigators have, in many cases, failed to identify the underlying root cause of shortfalls prior to the initiation of civil recovery action or criminal proceedings,” said Second Sight. In its own 83-page report, the Post Office said the Second Sight findings were wrong.

Horizon debated in Parliament

The Horizon dispute has been debated at the highest levels of UK government, with prime minister David Cameron stressing the importance of resolving the issues.

In February 2015, Post Office CEO Paula Vennells and programme director for branch support Angela van den Bogerd were questioned at a parliamentary select committee investigating the Horizon dispute.

At the hearing Katy Clark, then MP for North Ayrshire and Arran, said: "One of the issues that has been put to me is that there is a lack of qualified people within the Post Office hierarchy with whom it is possible for a subpostmaster to have a discussion when there is a technical issue to do with the Horizon system. What are you doing to improve that, for example, and what other lessons have you learned?

Vennells replied: “I would say that that isn’t true. If subpostmasters have queries, they can escalate them as high as they need to. I get phone calls and emails, and I personally take them on a regular basis."

Clark said: “But you are not an IT specialist?”

Vennells said: “If they have an IT query, I will immediately go to my CIO, and she [Lesley Sewell at the time, who has since left] is prepared to talk to any subpostmaster about it. The organisation wants to help subpostmasters to run Post Offices properly – of course we do – and we have put ourselves out as much as we possibly can. Where we have got it wrong, because human error happens, we have put in really significant changes in terms of the training and support that is available.”

Culture of denial

She said a branch user forum was set up for subpostmasters, “who are very critical of us, which is why we did it - to learn the things that we can improve”.

MPs have accused the Post Office of having a culture of denial and not looking for possible causes for unexplained losses. In December 2014, Mike Wood, then MP for Batley and Spen, said there were too many cases in doubt for the Post Office to hold its stance that there were no problems with the Horizon system.

“Either the Post Office is awash with criminals who open sub-post offices for personal gain or something has gone terribly wrong. MPs are inclined to believe the latter and we are all shocked the Post Office seems to not want to get to the bottom of all this,” said Wood.

In the select committee hearing in February, Angela van den Bogerd said: “Looking back over the cases that we have investigated, we could have done that a bit better in some of those cases. It is not that there is a culture of denial here. I have personally been involved in each of those 150 cases and got into the detail. Where we could have done better – it is only a handful of cases – we have absolutely said that. I cannot accept that we are in denial about that, because we are looking at it.”

There is a review underway of cases where subpostmasters were prosecuted in court, which is being carried out by the Criminal Courts Review Commission to decide whether criminal trials of subpostmasters accused of wrongdoing were fair.

Campaigners have called for an independent inquiry. “The only way we will get to the bottom of it is to have a truly independent inquiry, which Post Office is not involved in,” said one.

Timeline of events in the Horizon story

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