Redknapp, 64, who is facing charges of tax evasion which he denies, said he struggles with literacy, adding: "I write like a two-year-old and I can't spell."
The Press Association also reported that Redknapp, widely tipped as a future England manager, claimed he was "the most disorganised person in the world" during interviews with City of London detectives in 2009.
In tape recordings played at Southwark Crown Court, Redknapp said: "I can't work a computer, I don't know what an email is, I can't, I have never sent a fax and I've never even sent a text message."
He added: "I have a big problem, I can't write so I don't keep anything. I am the most disorganised person, I am ashamed to say, in the world."
Redknapp told officers he had not seen his pay slip in years as he said: "You talk to anybody at the football club. I don't write. I couldn't even fill a team-sheet in."
Under questioning over the Monaco account at the heart of the 189,000 pounds bung allegation, the Tottenham Hotspur manager added: "I pay a fortune to my accountant to look after me you know.
"He writes all the cheques for me and my wife. He pays my bills. He runs my life basically."
Redknapp told officers in June 2009 that The Sun newspaper, where he writes a regular column, "hadn't paid me for 18 months."
He said: "I've never wrote a letter in my life. I couldn't write a letter. I write like a two-year-old and I can't spell."
Redknapp added: "Why am I gonna fiddle 20, 30 whatever thousand pounds of income tax when I walk away six months later from £200,000 that I was due."
The tape was played out after jurors heard Redknapp made "disastrous" business decisions and lost 250,000 pounds in a "very unsuccessful" takeover bid at Oxford United.
Redknapp lost every penny as part of a loan to take control of Oxford, HSBC executive Alan Hills told the court.
Redknapp's barrister John Kelsey-Fry QC used the example to deny prosecution claims that the Tottenham Hotspur manager was a "hard-headed businessman".
He asked Mr Hills at Southwark Crown Court, in London: "Do you remember an occasion when he was persuaded to loan, at very short notice, 250,000 pounds to buy Oxford United and that money just disappeared into the mist?"
Mr Hills replied: "I have never seen it, yes."
Mr Hills said Redknapp had shown acumen in the property market, but he agreed with Mr Kelsey-Fry's claim that "with the benefit of hindsight, some investments were disastrous".
He added: "With regard to the shares [in Oxford United]... it is fair to say they were very unsuccessful."
Mr Hills, an associate director with HSBC in London between 2000 and 2009, said he held meetings with Redknapp alongside the football boss's solicitor and accountant.
The jury was told Mr Hills was not initially informed of Redknapp's Monaco dealings in addition to the domestic accounts he held with HSBC.
