Free tools Windows power users keep installed
One-click scans. No signup required.
Post Office figures reported by Computer Weekly show an average of six subpostmasters convicted each year from 1991 through 1998, compared with 52 a year from 1999 through 2012, after Horizon was introduced. Those figures put the scale of prosecutions into sharp focus, but they do not by themselves establish why each prosecution happened or settle the inquiry’s findings about former National Federation of SubPostmasters (NFSP) general secretary George Thomson.
How many subpostmasters were convicted before and after Horizon?
Computer Weekly, citing Post Office figures, reports the following comparison. The periods and averages should be read together: they are not a complete count of prosecutions, convictions later quashed, or everyone affected by the scandal.
| Period | Horizon context | Average convictions per year | Other reported detail |
|---|---|---|---|
| 1991–1998 | Before Horizon’s introduction in 1999 | 6 | The earlier comparison period reported by Computer Weekly. |
| 1999–2012 | After Horizon’s introduction and before the Post Office stopped prosecuting in 2013 | 52 | Annual figures ranged from 38 to 78, according to Computer Weekly. |
The second period spans 13 years, against seven years in the first. The averages therefore describe different-length windows, not a year-by-year account of the same circumstances. Computer Weekly also notes four convictions in 2015, after the Post Office had stopped prosecuting in 2013.
The comparison is stark: the reported annual average in 1999–2012 was markedly higher than in 1991–1998. It is evidence relevant to questions about the prosecution environment after Horizon arrived; it does not, on its own, prove that Horizon caused every prosecution or explain the facts of each case. Computer Weekly’s report.
#1 Best Overall
What did George Thomson say about Horizon and prosecutions?
Thomson was NFSP general secretary from 2007 to 2018, according to Computer Weekly. He gave evidence to the Post Office Horizon IT Inquiry on 21 June 2024. The official hearing page records his evidence in phases 5 and 6, which included redress, access to justice, governance, stakeholder engagement, oversight and whistleblowing.
In the account published by Computer Weekly, Thomson said suspensions and prosecutions had also occurred under the manual system and that he continued to believe Horizon was robust. His witness statement, as quoted in the report, said: “The sheer volume of transactions against the small percentage of claims proves beyond any doubt that the system was robust.” The report contrasts that view with Justice Fraser’s 2019 High Court judgment, which it says found Horizon was not robust. These are Thomson’s stated position and the report’s description of the judgment, not a fresh finding about his evidence by the inquiry.
Former subpostmaster and campaigner Alan Bates, quoted by Computer Weekly, called Thomson ignorant of the facts about Horizon. That is Bates’s assessment, reflected in the original headline’s framing; it is not a formal inquiry conclusion. Computer Weekly’s coverage of Thomson’s evidence and Bates’s response.
What does the NFSP relationship add to the context?
The Guardian reported that Thomson said he had been “too trusting” of information from the Post Office, while denying that he was “too close” to the organisation or had betrayed NFSP members. It also reported that the NFSP signed a 15-year agreement with the Post Office in 2013 to represent subpostmasters, with annual payments exceeding £1 million from 2014–15 onwards.
The Tool Desk
Outbyte Driver Updater FREEFix the driver behind crashes, sound loss and screen glitchesFind Drivers →Outbyte PC Repair FREEClear out junk files and repair common Windows errorsFree Scan →The agreement and payments are relevant background to scrutiny of the federation’s relationship with the Post Office. They do not, by themselves, prove Thomson’s motive, establish that the arrangement caused his views, or determine whether the NFSP represented members adequately. The Guardian’s report on Thomson’s evidence and the NFSP relationship.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.What the conviction figures do—and do not—show
The comparison answers a narrow but important question: reported average subpostmaster convictions per year were substantially higher in 1999–2012 than in 1991–1998. It is a reason to examine the change and the systems and decisions operating during those periods, not a substitute for case-level evidence.
Rank #4
- The figures are convictions as reported by Computer Weekly from Post Office data; they are not a full tally of prosecutions or all people affected.
- The averages cover distinct windows, with different lengths, and the later period’s yearly count varied from 38 to 78.
- The figures alone do not establish the cause of an individual prosecution or adjudicate Thomson’s credibility.
The inquiry’s scale underscores why its conclusions must be distinguished from commentary about an individual witness. In a 17 December 2024 notice, the inquiry reported counsel Jason Beer KC’s closing-submissions figures: 270,785 documents disclosed to core participants, amounting to 2,214,858 pages; 780 witness statements obtained; and 298 witnesses heard. Beer described the inquiry as being about people whose health, relationships and lives had been affected. These totals convey the breadth of the inquiry, but do not state a final finding specifically about Thomson or the NFSP. Post Office Horizon IT Inquiry notice on closing submissions.
Quick Recap
Best Value
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
