More than 700 Post Office branch managers were given criminal convictions after faulty Fujitsu accounting software called Horizon made it appear as though money was missing from their shops.
Here is a timeline of the key events of the scandal:
●1999
The Horizon IT system starts to be rolled out in Post Office branches across the UK.
● 2000
Alan Bates reports issues with the Horizon IT system.
● 2003
Mr Bates has his contract terminated after refusing to accept liability for the shortfalls in the accounts at his Llandudno branch in North Wales.
●2004
Lee Castleton, from Bridlington, East Yorkshire, was found to have a £25,000 shortfall at his branch.
He was made bankrupt after he lost his legal battle with the Post Office.
● 2009
Computer Weekly magazine breaks the story of seven sub-postmasters beginning their fight for justice.
The Justice for Subpostmasters Alliance is established.
● 2010
Pregnant sub-postmaster Seema Misra, who ran a post office in West Byfleet, Surrey, is jailed for 15 months after being accused of stealing £74,000.
● 2015
Post Office boss Paula Vennells tells the business select committee that there is no evidence of miscarriages of justice.
Post Office halts prosecutions of sub-postmasters.
● 2017
Legal action is launched against the Post Office by a group of 555 sub-postmasters.
● 2019
A High Court judge rules that Horizon contained a number of “bugs, errors and defects” and there was a “material risk” that shortfalls in Post Office branch accounts were caused by the system.
The Post Office agreed to pay out £58million to the 555 sub-postmasters.
Post Office boss Paula Vennells is appointed a CBE.
● 2020
The Post Office does not oppose 44 appeals against convictions of sub-postmasters.
Mr Justice Fraser sends a confidential letter to the Director of Public Prosecutions naming two former Fujitsu IT professionals.
Anne Chambers and Gareth Jenkins were expert witnesses in trials of sub-postmasters.
The Metropolitan Police launch an investigation.
● 2021
A statutory inquiry looking into the failings of the Horizon system and the wrongful convictions of sub-postmasters begins.
The Court of Appeal quashes 39 wrongful crown court convictions.
● 2023
The Government announces that every wrongly convicted sub-postmaster will be offered £600,000 in compensation.
● 2024
ITV drama Mr Bates vs The Post Office airs for the first time.
The Metropolitan Police say they are looking at “potential fraud offences arising out of these prosecutions”, for example “monies recovered from sub-postmasters as a result of prosecutions or civil actions”.
