National newspaper reporters routinely fiddled their expenses for years, Graham Dudman, the former managing editor of the Sun, told a trial today.

Giving evidence at The Sun corruption case, Mr Dudman said that when he started doing casual reporting shifts on the Daily Mail in 1987 he was taken to one side by a senior colleague and told to claim about £100 expenses a week, because it was the going rate.

Foreign expenses were particularly “heavily padded”, the News International executive told Kingston Crown Court, recalling a trip to Dubai where a Daily Express reporter arranged for a printer to churn out blank receipts which were filled in by reporters.

Mr Dudman said that his attitude to expenses changed when he became managing editor of the Sun and became responsible for policing reporters’ expenses himself.

He and five other past and present Sun executives are on trial for making or approving allegedly illegal cash payments to public officials.

Mr Dudman himself is charged with three counts of conspiring to commit misconduct in a public office.

Entering the witness box for the first time in the two-month trial, the 51-year-old was asked about his early career in newspapers.

In answer to questions from his lawyer Oliver Blunt QC, he said that he had worked his way up from the Middlesborough Evening Gazette to the Daily Mail and then Daily Express, where he did casual shifts in 1987.

Asked about the culture of claiming expenses in those day, he said they were bulked out because overtime was not paid and expenses were seen as an “allowance.”

Mr Dudman said: “When I joined the Daily Mail as a casual reporter in 1987, I was taken aside by one of the senior reporters and told that every week I should be claiming around £100 a week expenses."

Some of them would relate to work and some of them would not...“It was just your receipts and expense claims should be around the £100 mark. The news editor knew it...“The phrase was: ‘If you're doing well, put some more exes in'."Asked by his lawyer if the same culture existed at the Daily Express, Mr Dudman replied: "Yes." Fleet Street reporters would exchange stories about going rates and expenses claims when they met out on stories, he said, telling the court that over claiming expenses was “industry wide culture."

He said that the Daily Mail, Mirror and the Sun “had the best exes.”

When he joined the Sun in 1990 as a reporter – before rapidly rising through the ranks – he found the culture very much intact.

He said: “You were expected to claim desk exes, because that was what everybody would do. It was the unwritten rule... there were no written formal instructions on how many you should claim. Some people would claim £200 a week.”

Of foreign expenses, he said: "There wasn't an allowance... but there was an unwritten rule of around £100 a day expenses [which would include translators, meals and taxis].”

Mr Dudman told the court: "A lot of the foreign expenses were padded very heavily… you would create receipts.” He said that “every now and then” at News International there would be an expenses purge “and they would say you need to reduce your expenses by 10 per cent.”

Of The Sun’s overall editorial budget last year of £63million, he told the court that about £5m went on expenses.

He gave an impression of the Sun’s newsroom in Wapping as a casual place to work.

Rebekah Brooks, he said, had written down his job description on a Post-it note, which included bullet points such as PCC [Press Complaints Commission], staff performance, Project Hal [a move to new printing plants], and corporate news.

As well as overseeing hiring and firing, complaints to the newspaper and relationships with columnists such as Lorraine Kelly and Jeremy Clarkson, Mr Dudman was responsible for expenses and contributor payments.

About one half of one per cent of the Sun’s contributor payments were paid in cash, he said.

The cash was kept in a safe in his office. How much cash was kept in the safe, asked Mr Blunt.

“£25,000” replied Mr Dudman, adding that the amount was kept topped up to that level.

He said people who didn’t want to be paid by bank transfer included "people who didn't have a bank account, people who didn't want their spouses to know they were selling a story to the newspaper.”

Asked how much training there was at The Sun on how to write articles or which terminology to use, Mr Dudman told the court: "None". He added: "There was training in relation to management and HR and employment law."

He and the other Sun journalists – including head of news Chris Pharo and former deputy news editor Ben O’Driscoll – deny all charges. The case continues.