The British Post Office scandal, sometimes called the Horizon IT scandal, arose from faulty software, provided by Fujitsu and known as Horizon, creating false shortfalls in the accounts of thousands of subpostmasters. It has been described as one of the most widespread miscarriages of justice in British history. Between 1999 and 2015, over 900 subpostmasters were convicted of theft, fraud and false accounting based on faulty Horizon data, with about 700 of these prosecutions carried out by the Post Office. Other subpostmasters were prosecuted but not convicted, forced to cover Horizon shortfalls with their own money, or had their contracts terminated. The court cases, criminal convictions, imprisonments, loss of livelihoods and homes, debts and bankruptcies, took a heavy toll on the victims and their families, leading to stress, illness, family breakdown, and at least four suicides.
Although many subpostmasters had reported problems with the new software, the Post Office insisted that Horizon was robust and failed to disclose its knowledge of faults in the system while securing convictions. In 2009, Computer Weekly broke...