luisfpizarro - Fotolia

Tech under spotlight at High Court in second subpostmasters versus Post Office trial

The second trial in a court battle between the Post Office and the people who run branches analyses alleged bugs in the computer system they use

A High Court trial between subpostmasters and the Post Office will focus on the computer system and supporting services at the centre of the long-running dispute.

This, the second trial of a group litigation order (GLO) brought by more than 500 subpostmasters, will take place in the Rolls Building of the High Court on Fetter Lane, London.

A decade ago, Computer Weekly revealed that the lives of some subpostmasters, who run Post Office branches, were turned upside down as a result of being fined, sacked, made bankrupt and even imprisoned because of unexplained accounting shortfalls.

They blame the accounting system from Fujitsu, known as Horizon, for the problems. Horizon, which was introduced in 1999/2000, is used by nearly 12,000 post offices, and subpostmasters are held liable for any unexplained losses (see timeline below).

The latest trial, which is expected to run for a month, will hear witness statements from computer experts and throw thousands of known computer errors into the public eye.

One disclosure in the trial is the known errors log, which records errors in the Post Office Horizon retail and accounting system and supporting services used by subpostmasters. It will reveal thousands of bugs, hundreds of which could potentially be capable of leading to losses for subpostmasters. Claimants say they experienced life-changing hardship after being punished for losses, for which they blame the computer system.

The Post Office has always denied the allegations about Horizon, and said there were no problems with the system that could have caused unexplained losses for subpostmasters.

“We have confidence in the Horizon system, which is robust, reliable and used across 11,500 branches by postmasters, agents and their many thousands of staff to process millions of transactions successfully every day, including on behalf of the UK’s high street banks,” said the Post office in the first trial in November 2018.

In 2009, Computer Weekly told the stories of seven of the postmasters affected. Some received heavy fines and had to repay thousands of pounds because of unexplained shortfalls in their accounts. Some lost their life savings and went bankrupt. Others subpostmasters were sent to prison, one while pregnant.

Evidence reveals known problem with Horizon

The first trial in November focused on the contractual relationship between the Post Office and the subpostmasters who manage its local branches.

But the computer system’s alleged faults were a constant theme during the trial. Documents referred to in court revealed evidence of a known problem with Horizon described by the Post Office and its IT partner Fujitsu.

A Post Office internal memo from August 2010, referred to in court and entitled Receipts payments mismatch issue memo day 1 OP_0008387, revealed that discrepancies showing at the Horizon counter disappear when the branch follows certain process steps, but will still show in the back-end branch account.

A Post Office internal memo from August 2010 revealed that discrepancies showing at the Horizon counter disappear when the branch follows certain process steps, but will still show in the back-end branch account

The memo added that this issue could be damaging if revealed. “If widely known, it could cause a loss of confidence in the Horizon system,” the memo said. “There could be a potential impact upon ongoing legal cases where branches are disputing the integrity of Horizon data. It could provide branches with ammunition to blame Horizon for future discrepancies.”

During cross-examination, Post Office director Angela van den Bogerd admitted that the Horizon IT system had made mistakes, which the Post Office was responsible for correcting, but said the Post Office did not necessarily have to tell its subpostmaster network about the errors. Van den Bogerd said the Post Office could have told subpostmasters about the errors, but did not.

The judgment form the first trial is expected to be handed down and available to the public this week. It is expected to give full analysis and findings on the 23 separate issues addressed in the first trial, as well as observations and findings on the evidence given by the witnesses for both sides.

During the first trial, Post Office QC David Cavender described the case as an “existential threat” to the Post Office’s business model. It is currently one of the biggest cases in the UK, and will span at least four trials and extend into 2020.

A third trial, scheduled for October 2019, will focus on individual subpostmasters’ claims, and a fourth trial will probably be held in early 2020.

Meanwhile, Post Office CEO Paula Vennells has had an eventful few months since the first trial. In January she received a CBE in the New Year’s honours list and last month it was announced she is leaving the Post Office to take up the role of chair of Imperial College Healthcare NHS trust.

Separately, the Criminal Courts Review Commission (CCRC) is reviewing about 30 claims from subpostmasters that they were wrongfully prosecuted as a result of problems with the Post Office’s Horizon system.

The CCRC was expected to announce its decisions on the cases under review, but will now wait until after the judge’s ruling on the first trial in the GLO. It might then decide to wait until after the current trial.

The case continues.

For live tweeting from court, see the Twitter account of broadcast journalist Nick Wallis. Also read his Post Office trial blog.

Timeline of the Post Office Horizon case since Computer Weekly first reported on it in 2009

May 2009: Bankruptcy, prosecution and disrupted livelihoods – postmasters tell their story

September 2009: Postmasters form action group after accounts shortfall

November 2009: Post Office theft case deferred over IT questions

February 2011: Post Office faces legal action over alleged accounting system failures

October 2011: 85 subpostmasters seek legal support in claims against Post Office computer system

June 2012: Post Office launches external review of system at centre of legal disputes

January 2013: Post Office admits Horizon system needs more investigation

January 2013: Post Office announces amnesty for Horizon evidence

January 2013: Post Office wants to get to bottom of IT system allegations

June 2013: Investigation into Post Office accounting system to drill down on strongest cases

July 2013: Post Office Horizon system investigation reveals concerns

October 2013: End in sight for subpostmaster claims against Post Office’s Horizon accounting system

October 2013: Former Lord Justice of Appeal Hooper joins Post Office Horizon investigation

November 2013: 150 subpostmasters file claims over ‘faulty’ Horizon accounting system

September 2014: Fresh questions raised over Post Office IT system’s role in fraud cases

December 2014: MPs blast Post Office over IT system investigation and remove backing

December 2014: Why MPs lost faith in the Post Office’s IT investigation, but vowed to fight on

December 2014: MPs to debate subpostmaster IT injustice claims

December 2014: MP accuses Post Office of acting “duplicitously” in IT investigation

January 2015: MPs force inquiry into Post Office subpostmaster mediation scheme

January 2015: Post Office faces grilling by MPs over Horizon accounting system

February 2015: Post Office CIO will talk to any subpostmaster about IT problems, promises CEO

March 2015: Post Office ends working group for IT system investigation day before potentially damaging report

March 2015: MPs seek reassurance over Post Office mediation scheme

March 2015: Retiring MP aims to uncover truth of alleged Post Office computer system problems

April 2015: Post Office failed to investigate account shortfalls before legal action, report claims

April 2015: Criminal Courts Review Commission set to review subpostmasters’ claims of wrongful prosecution

May 2015: IT system related to subpostmaster prosecutions under review by CCRC

June 2015: Post Office looking to replace controversial Horizon system with IBM, says MP

July 2015: Campaigners call for independent inquiry into Post Office Horizon IT system dispute

October 2015: James Arbuthnot takes Post Office IT fight to House of Lords

November 2015: The union that represents Post Office subpostmasters has warned of a problem with the Horizon accounting system

November 2015: An email from Post Office IT support reveals a problem with the Horizon system and supporting processes that could lead to accounting errors

November 2015: Group litigation against Post Office being prepared in Horizon dispute

February 2016: Post Office faces group litigation over Horizon IT as subpostmasters fund class action

June 2016: Post Office chairman Tim Parker says there would be “considerable risk” associated with changing its Horizon computer system

November 2016: The legal team hired by a group of subpostmasters will take their case to the next stage

January 2017: The group action against the Post Office that alleges subpostmasters have been wrongly punished for accounting errors gets a green light from the High Court of Justice

March 2017: 1,000 subpostmasters apply to join IT-related group litigation against Post Office

April 2017: Investigation into claims of miscarriages of justice in relation to a Post Office accounting system has appointed a forensic accountant firm

May 2017: Hundreds of subpostmasters have applied to join IT-related legal action since March

July 2017: Post Office defence in computer system legal case due this week

August 2017: Campaigners submit initial evidence in group litigation against Post Office over controversial Horizon IT system

October 2017: Subpostmasters’ group action against the Post Office reaches an important milestone

November 2017: An end is in sight for subpostmasters’ campaign against alleged wrongful prosecution, which they blame on a faulty computer system

November 2017: The high court judge managing the subpostmasters versus Post Office legal case over an allegedly faulty computer system tells legal teams to cooperate

January 2018: Forensic investigation into Post Office IT system at centre of legal case nears completion

April 2018: Criminal Cases Review Commission forensic examination of the IT system at the centre of a legal case against the Post Office has raised further questions

May 2018: Post Office branches unable to connect to Horizon computer system for several hours after morning opening time

October 2018: After over a decade of controversy, next week marks the beginning of a court battle between subpostmasters and the Post Office

November 2018Case against Post Office in relation to allegedly faulty computer system begins in High Court

November 2018: High Court case in which subpostmasters are suing the Post Office has revealed a known problem with a computer system at the core of the dispute

November 2018A High Court trial, where subpostmasters are suing the Post Office for damages caused by an allegedly faulty IT system, ends second week

November 2018: Post Office director admits to Horizon errors and not sharing details with subpostmaster network

November 2018: The High Court trial in which subpostmasters are suing the Post Office has reached an important stage

December 2018: CCRC may hold off subpostmaster decision until after Post Office Horizon trial

December 2018: Court case where subpostmasters are suing the Post Office set to span at least four trials and extend into 2020

January 2019: Subpostmasters’ campaign group attacks Post Office CEO Paula Vennells’ New Year honour amid ongoing court case

January 2019: Thousands of known errors on controversial Post Office computer system to be revealed

Read more on Financial applications

Data Center
Data Management