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The CCRC and Post Office/ Horizon cases 

The Post Office Horizon scandal, which is the subject of the ITV drama Mr Bates vs The Post Office, is the most widespread miscarriage of justice the CCRC has ever seen and represents the biggest single series of wrongful convictions in British legal history.  

It relates to the wrongful prosecutions of former sub-postmasters (individuals who run independent Post Office branches on behalf of Post Office Ltd) for theft, fraud and false accounting.  

The IT system used in both independent and Crown Post Offices was known as Horizon, developed and operated by Fujitsu Ltd on behalf of Post Office Ltd. 

By recording transactions, Horizon calculated how much cash and stock should be in an individual branch. The sub-postmaster was expected to count the cash held at their branch each day and enter a daily cash declaration on to Horizon.  

Horizon appeared to have significant bugs which could cause the system to misreport, sometimes involving substantial sums of money which sub-postmasters found difficult to challenge as they were unable to access information about the software to do so.  

The convictions which the CCRC was later asked to review typically arose after Post Office Ltd auditors found that the physical cash and/or stock in a particular branch was less than that declared by the sub-postmaster, leading to their prosecution. 

Alleged problems with the Horizon system were first reported by Computer Weekly in 2009. There were concerns that faults in the system were causing it to overstate the amount of cash or stock which should be on the premises of a particular branch. 

Post Office Ltd appointed a firm of forensic accountants who concluded that that “in some circumstances Horizon can be systemically flawed from a user’s perspective and Post Office has not necessarily provided an appropriate level of support”.

After more than 900 prosecutions, around 580 sub-postmasters and Crown Office employees initiated civil proceedings against Post Office Ltd during which Post Office agreed to pay damages.  

From March 2015, the CCRC received applications from a large number of individuals who had been convicted of offences. 

The CCRC’s review of Post Office cases was large scale and complex with investigations across numerous strands of enquiry, including the expert insights of forensic accountants.  

The CCRC referred a significant number of convictions to the appeal courts on two grounds relating to abuse of process.  

In its judgment in the case of Hamilton & Others v Post Office Limited in April 2021, the Court of Appeal concluded that in all cases in which the reliability of Horizon data was essential to the prosecution and in which there was no independent evidence of an actual loss, the trial process could not be fair (the first ground).  

In each case where ground one was made out, it was an affront to the public conscience for the appellants to face prosecution (ground two) and therefore this ground was made out as well.  

The Court stated that it was “satisfied that a fair trial was not possible in any of the Horizon cases” and that “…the failures of investigation and disclosure were in our judgment so egregious as to make the prosecution of any of the ‘Horizon cases’ an affront to the conscience of the court”.

The Court of Appeal in Hamilton dismissed the appeals in three cases which the CCRC had referred, concluding that Horizon data had not been essential to the prosecution in any of those three cases.  

The Court went on to say they had no doubt that all the guilty pleas of the successful appellants in the Horizon cases were founded upon Post Office Ltd’s failures of investigation and disclosure and that many of the sub-postmasters may have felt they had no real alternative but to plead guilty. 

The CCRC continues to seek potential Post Office applicants and continues to refer cases to the Court of Appeal.  

You can find out more about the Post Office scandal and how to challenge a Horizon-related conviction or sentence on the CCRC website

You can also read about some of the first convictions to be sent back to the Court of Appeal as a result of CCRC references here.  

Notes to Editors       

  1. The CCRC is an independent body set up under the Criminal Appeal Act 1995. It is responsible for independently reviewing suspected and alleged miscarriages of criminal justice in England, Wales and Northern Ireland. It is based in Birmingham and is funded by the Ministry of Justice.    
  2. The CCRC investigates potential miscarriages of justice and is the only organisation in England, Wales and Northern Ireland that can refer cases back to the court for appeal.    
  3. Access to the CCRC service is free and there is no time limit in applying.     
  4. There are currently 10 Commissioners who bring to the CCRC considerable experience from a wide variety of backgrounds. Commissioners are appointed by the monarch on the recommendation of the prime minister in accordance with the Office for the Commissioner for Public Appointments’ Code of Practice.       
  5. The CCRC usually receives around 1,400 applications for reviews (convictions and/or sentences) each year. Since starting work in 1997, the CCRC has referred around 3% of applications to the appeal courts.       
  6. The CCRC considers whether, as a result of new evidence or argument, there is a real possibility that the conviction would not be upheld were a reference to be made. New evidence or argument is argument or evidence which has not been raised during the trial or on appeal.  Applicants should usually have appealed first. A case can be referred in the absence of new evidence or argument or an earlier appeal only if there are “exceptional circumstances”.       
  7. If a case is referred, it is then for the appeal court to decide whether the conviction is unsafe or the sentence unfair. More details about the role and work of the Criminal Cases Review Commission can be found at The CCRC can be found on Twitter @ccrcupdate    
  8. Post Office convictions cannot be referred to the appellate courts en masse – Blog: Why all Post Office convictions cannot be referred at once – Criminal Cases Review Commission (