As the public investigation into the Horizon scandal moves forward, representatives of the Post Office, the government, and the Japanese company Fujitsu are scheduled to testify.

The scandal has been described as the most widespread miscarriage of justice in UK history, which saw more than 700 Post Office branch managers handed criminal convictions.

Although the High Court judge indicated he would submit Fujitsu to the Director of Public Prosecutions for potential further action because he had “grave concerns” about the company’s employees’ testimony, nobody from the Post Office or Fujitsu has been held accountable thus far.

What is the Horizon computer scandal?

Starting in January 1999, Horizon was introduced into the Post Office network. The system was used for transactions, accounting, and stocktaking and was created by the Japanese corporation Fujitsu.

As soon as the system detected shortages, some of which totaled several thousand pounds, sub-postmasters complained about faults in the system after the software made it appear as though money was missing. Some sub-postmasters made (often futile) attempts to fill the hole with their own money, even remortgaging their homes.

Based on the data from the system, the Post Office prosecuted 736 sub-postmasters and sub-postmistresses between 2000 and 2014, or one per week on average.

As a result, following convictions for theft and false accounting, some were sent to prison; many others experienced financial collapse and have spoken of being shunned by their communities. Some have now passed away.

Today, campaigners won a legal struggle after 20 years, arguing that the computer system was broken, to have their cases reexamined.

Does the Post Office still use Horizon?

According to the Post Office’s website, Horizon is still being used.

“The current version of the system, introduced from 2017, was found in the group litigation to be robust, relative to comparable systems. But we are not complacent about that and are continuing to work, together with our postmasters, to make improvements.”

However, the website adds it will be moving away from Horizon to a new IT cloud-based system, which will be “more user friendly and easier to adapt for new products and services”.

How many people were wrongfully blamed?

After a protracted string of legal lawsuits, the Post Office reached a settlement with 555 claimants in December 2019.

It acknowledged that it had "gotten things wrong in [its] dealings with a number of postmasters" in the past and consented to pay £58 million in compensation.

After legal bills were paid, the claimants received a portion of £12 million.

Following the High Court decision, more cases were submitted to the Criminal Cases Review Commission (CCRC), an impartial agency that looks into possible injustices.

The convictions of a total of 72 former postmasters have already been overturned in court decisions, and additional cases are anticipated.

The Post Office has agreed to pay out compensation as soon as feasible to those whose convictions, supported by Horizon evidence, have been overturned.

Applications for interim compensation up to £100,000 are being accepted, with the government covering the cost.

Final agreements will be reached through mediation or by filing lawsuits in civil courts.