Sun journalist Jamie Pyatt told Kingston Crown Court said Sun reporters routinely fiddled their expenses as compensation for working long hours in a tough environment.
Pyatt was giving evidence as he stood trial along with five colleagues from the paper accused of making illegal payments to public officials.
He said it was the "culture" across Fleet Street to claim for meeting a contact, when in fact reporters and journalists were enjoying a meal out.
But he said while expenses forms were falsified, he never claimed money from The Sun that he had not spent himself.
"The expense system was authorised but in a sense an unauthorised method of overtime that was given to the journalist as we didn't get overtime", he explained.
"It was an accepted practice at The Sun that if you put in a long day, especially if it was a successful day, you finish with your photographer, have a meal and a couple of beers, and you will submit an expense accordingly."
Judge Marks interjected: "Putting it down as if you had been entertaining a contact but you had not?"
Pyatt said: "If I had been working on a murder until 8pm at night, I would write down entertaining police press officer or entertaining a senior police contact.
"If I took the wife out, it was only as a result of something the newsdesk said was acceptable.
"Sometimes what you put down as the reason for the expenses may be untrue.
"But the expenditure was always there."
Pyatt said a senior Sun journalist sat him down in 1987 to explain how the expenses system worked.
"The established practice was for journalist to pay the photographer's dinner, and claim it back as an expense as having been a source", he said.
"In 1987 I submitted my first set of expenses and was taken to task because they were far lower than everybody else's.
"I was sat down with an experienced reporter who redid my expenses for me, to show me roughly where to pitch them in relation to my colleagues.
"We did not get overtime, it was part of your package.
"That was the culture, it was what everybody in Fleet Street did across the board for the newspapers."
He said senior and specialist reporters were allowed to claim more than junior members of staff, and this was a widely accepted practice.
Pyatt said he had spotted many mistakes in his expenses during the trial, claiming for a meal with a murder squad detective before the crime had been committed, and claiming expenses for meeting Simon Quinn while it was in Iraq.
But he said all the expenses had been incurred by him in the course of his work in some way.