Harry Redknapp told police "I write like a two-year-old and I can't spell" as he denied taking bungs, a court heard today.
He also told officers: "I have never written a letter in my life."
Jurors heard a tape recording of the Tottenham Hotspur manager being taken in for questioning by City of London Police.
Redknapp said: "I am completely and utterly disorganised. I am not going to fiddle taxes, I pay my accountant a fortune to look after me."
He also told officers of a feud with Milan Mandaric over a bonus he was due for the sale of Peter Crouch from Portsmouth to Aston Villa.
Regarding his relationship with Mandaric, Redknapp added: "I was getting bigger than him at the football club and he didn't like it really."
Redknapp said his co-defendant had not wanted him to sign Crouch in the first place.
Redknapp told police: "Mandaric told me 'He's useless. I think you are going to have to pay me 10%'."
When England striker Crouch was sold on for a £3million profit, Redknapp said he was due 10%.
But chief executive Peter Storrie said "you've only got 5% Harry" as he was due to sign a new deal, Redknapp claimed.
Redknapp said he then told Mandaric: "I don't want to end up with a tax bill."
The defendant said he had been told by Mandaric there was no tax "on so many occasions".
He added that the Monaco account was "as far as I was concerned, it was dead".
"I didn't even know what bank it was I walked into - and neither did my wife," Redknapp said.