The Fujitsu-developed system, used for accounting and stockpiling, was used as evidence to successfully prosecute 736 people between 2000 and 2014, out of which 42 maintained their innocence for over a decade.
It would later emerge that a system bug had produced financial shortfalls in branch accounts, resulting in unaccounted funds.
Many falsely convicted Post Office employees had their personal lives destroyed as a consequence of the convictions, having been sent to prison and denied insurance in many cases. Some have since passed away, unable to hear today’s verdict.
However, following years of legal battles, Lord Justice Holroyde at the Royal Courts of Justice in London said the Post Office knew there were serious issues about the reliability of Horizon and had a clear duty to investigate the system s flaws.