A former postmaster has said there could be an unknown number of Horizon scandal victims as small discrepancies could be attributed to minor human errors and easily corrected.

In an interview, Allenton Fisher, who used to run Okehampton’s Post Office, explained that because a post office deals with so much money a Horizon computer fault in a larger branch could be balanced out with a small accounting error somewhere else and go unnoticed by the postmaster.

He said: “In an office like Okehampton, which is quite decent size, if you are £200-£300 down one week, that’s not the end of the world. I know that sounds a lot of money, but you’re dealing in lots of money. Sometimes you’ve made a mistake by inputting it in the wrong way - a £500 bag of coins is actually only £200 or something like that. You wouldn’t notice it.”

Mr Fisher, who has also run post offices in Lincoln and was a member of the National Federation for Subpostmasters, never had noticeable problems with the Horizon software. Just like Alan Bates, he also refused to sign off on any account sheets that did not add up to avoid becoming liable for any discrepancies if the auditors visited.

Mr Fisher said: “If the auditors walk in on a Thursday morning and that money is not there, you’re out of contract and they can get rid of you. If I was down, I either didn’t sign the cash account and said there must be something wrong and I want to check it all again tomorrow. If you sign the cash account, you’re saying that’s correct. Most postmasters are very wary of auditors.”

Auditors never informed postmasters prior to their visit and, under Post Office rules, postmasters could not open in the morning unless the accounts balanced the night before.

However, for some village post offices even a small apparent loss could represent a large percentage of the day’s earnings and they were unable to make up the shortfall, even if accounting errors were identified. As a result, some postmasters felt compelled to sign off on accounts as they could not afford to lose a day’s trading. 

“I really do feel for these people,” said Mr Fisher. “I’ve lost money through theft, I’ve lost money through errors, and I’ve never found it. But I can’t say hand on heart that it has anything to do with Horizon.”

Mr Fisher added that the Horizon scandal will affect how the public will view the Post Office but has urged British people to continue to trust their postmaster or postmistress as many people choose to run post offices to help the community.

Just as many people across the country are doing, Mr Fisher has questioned why the Post Office did not query the sudden rise in prosecutions following the introduction of the Horizon system.

“In the 70s and 80s there would have been so many so many people who have been done for fraud. In the 2000s that went ballistic,” said Mr Fisher.

“No postmaster gets rich, but you do it because you like it, because it’s a part of the community. They’re community people.

“The Post Office was our friendly shop. You could go in and say to the counter person ‘I’m new here can you tell me how we do this?’ That’s what we do. Everybody likes that and I think that view is going to change now.”

Between 2000 and 2015, over 700 subpostmasters and subpostmistresses were convicted of theft, fraud and false accounting due to the faulty Horizon system which incorrectly showed shortfalls in branch accounts. Some received prison sentences, others went bankrupt and many lost their reputation within their communities.

Following the broadcast of the ITV drama Mr Bates vs The Post Office, public support for the postmasters has encouraged the Government to act. Last week, Prime Minister Rishi Sunak announced that the Government would introduce a law to overturn the convictions of all Horizon scandal victims.

Many have welcomed the news, but others think that justice is too slow.

Mark Wooding, Liberal Democrat parliamentary candidate for Central Devon, said: “Over 40 years to get justice for innocent victims. In that time many have died. This is not how justice should work.”