Exclusive: software believed to have resulted in prosecutions even before full system rollout in 1999

• What is the Post Office Horizon IT scandal all about?
• ‘I got tarred overnight’: how Post Office Horizon scandal turned victims’ lives upside down

The Post Office is suspected of wrongly prosecuting dozens more operators who took part in a pilot scheme of the faulty Horizon system, the Guardian has been told.

Amid growing anger over the treatment of postmasters whose lives have been ruined in the scandal, Whitehall sources have confirmed that a precursor scheme was rolled out in 1995 and 1996 to hundreds of branches in north-east England.

Annual results show it holds only £244m for payments to wrongly convicted branch managers, after fewer appeals than expected

The Post Office has almost halved the amount set aside for payments to branch managers wrongly convicted in the Horizon IT scandal as fewer than expected have won or brought appeals.

The scandal, frequently described as “the most widespread miscarriage of justice in UK history”, resulted in more than 700 post office operators being prosecuted between 1999 and 2015 for theft, fraud and false accounting because of faulty accounting software installed in the late 1990s.

Wyn Williams calls for legislative change to resolve issues for those affected by the scandal

Schemes set up to compensate former post office operators wrongly accused of crimes are “a patchwork quilt” with “holes in it” that are likely to miss the deadline to pay up, the chair of the inquiry into the scandal has said.

More than 700 people were prosecuted for theft and false accounting between 2000 and 2014 after the Post Office’s flawed Horizon IT system incorrectly suggested there were financial shortfalls.

In the UK and Ireland, Samaritans can be contacted on freephone 116 123, or email jo@samaritans.org or jo@samaritans.ie. In the US, you can call or text the National Suicide Prevention Lifeline on 988, chat on 988lifeline.org, or text HOME to 741741 to connect with a crisis counselor. In Australia, the crisis support service Lifeline is 13 11 14. Other international helplines can be found at befrienders.org

At least 170 wrongly accused branch managers told they may not be repaid because they missed deadline

Scores of post office operators wrongly accused of embezzlement by the Post Office due to faulty accounting software, may be disqualified from a dedicated compensation scheme.

At least 170 branch managers have been told that they may not be repaid money wrongly deducted from their wages in what has been described as “the biggest miscarriage of justice in UK history” because they were unaware of the scheme, which was launched for just three months during the 2020 lockdown.