Over 1,000 subpostmasters whom the Post Office accused of dipping into the tills — wrongly, many complained, citing problems affecting the Post Office's Horizon IT system — could be set to join a group litigation order to clear their names.

According to the legal firm Freeths, which is leading the action, hundreds of affected subpostmasters have come forward since a group litigation order was granted in January regarding the Post Office's treatment of contractors, and many more may do so before the deadline for joining the collective action on the 26 July, according to The Observer, which reported that there would potentially be a "payout of tens of millions to the subpostmasters, who say that a faulty IT system led to accounting shortfalls."

“Our claim goes back to 1999, the year when the Horizon IT system was installed,” James Hartley, a partner with Freeths, told The Observer, adding that “there are thousands and thousands of subpostmasters out there who may be entitled to join the group claim … the potential pool of claimants is very significant, but we just don’t know how many people will come forward over the next few months.”

These IT issues have been stressed by those affected for a long time. Back in 2013, the Post Office admitted that it may have wrongly prosecuted subpostmasters due to issues affecting the Horizon IT system, which continues to handle all payment processing for the Post Office's 11,500 contractors who run sub–post offices throughout the country.

A forensic accountancy group, Second Sight, was appointed in 2012 by the Post Office — at the request of MPs — to conduct an independent investigation into matters raised by former and current subpostmasters. Its report alleged that the Post Office failed to find out why large cash shortfalls had occurred at several subpost offices before it began launching civil litigation and criminal prosecutions against subpostmasters, who are contractually liable for such losses.

In 2015, the Post Office refuted the findings of that report, which concluded that the Horizon IT system was in fact responsible for the accounting cockups which led to many subpostmasters losing their jobs and being made bankrupt, with some being prosecuted for theft and false accounting, with one documented suicide of those who were affected.

At the time, the Post Office said that the investigators were unable to show evidence to support their allegations regarding the Horizon system, with a spokesman telling The Register: "Over the past three years there have been exhaustive investigations which have not found any evidence of systemic problems with the Horizon system."

Responding to such a claim, the former Conservative MP James Arbuthnot, who led a Parliamentary campaign in support of the sub-postmasters, told the BBC that "if you go through the report that Second Sight has produced it is crammed full of evidence, except ... that which the Post Office has been withholding from Second Sight ... the emails that Second Sight needs [and] access to the documents that the Post Office promised to provide."

In a statement, the Post Office said that it "welcomes the group litigation order as offering the best opportunity for the matters in dispute to be heard and resolved. We will not otherwise comment on litigation while it is ongoing. We continue to have confidence in the Horizon system, which has around 78,000 users across 11,600 branches nationwide to process six million transactions a day." ®