Ooops !
https://www.bbc.co.uk/news/articles/cqlkx6n15ero
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The Post Office and Fujitsu agreed a deal 19 years ago to fix transaction errors in sub-postmasters' accounts caused by bugs in the Horizon IT system, a document has revealed.
An agreement was in place in 2006 for errors caused by bugs in the software to be corrected, or for Fujitsu to pay the Post Office up to £150 per transaction if it failed to do so.
The revelation directly contradicts the Post Office's claims during criminal prosecutions - which led to hundreds of wrongful convictions and civil cases that destroyed livelihoods - that no bugs existed capable of causing accounting shortfalls.
It also shows the Post Office knew almost two decades ago that Horizon could not always be relied upon to record transactions accurately."
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"The document, external indicates the formal commercial arrangement was drawn up to deal with potential mismatches or "discrepancies" and where Fujitsu's system was responsible, it was expected to correct false transactions or pay "liquidation damages".
The disclosure also undermines the Post Office's claim to the media and before Parliament in 2015 that it was not possible for Fujitsu to alter sub-postmasters's transactions without their knowledge.
"The Post Office conducted both the criminal trials of postmasters and the group litigation of 2019 on the basis that it knew of no substantial problems with the Horizon system," said Paul Marshall, senior barrister for sub-postmasters.
"Yet this shows that in 2006 there was a very big, recognised problem with Horizon maintaining data integrity between Post Office branch offices and Fujitsu," he added.
"The Post Office, for 20 years, was saying the only explanation for shortfalls in branch accounts was postmaster incompetence or dishonesty.
"But the maintenance of data integrity was fundamental to the Post Office-Fujitsu contract - Fujitsu were unable to provide or assure this."
The document implicitly acknowledges that data held on Horizon's servers at Fujitsu's headquarters could fail to match the transactions sub-postmasters had carried out at their branches."