A failure to properly compete a police form asking for driver information landed a company director with a bill for £1,775 from Skipton magistrates.
Benjamin Lack, 40, told the court on Monday that it was either him or his partner who was driving the Porsche 911 caught on a speed camera doing 83mph on the A59 at Draughton in June last year.
He said because he could not be absolutely sure and because photographic evidence had been inconclusive, he did not want to give false information to the police.
The court heard he had been sent a notice of intended prosecution and reminders and he, and his solicitors, had responded with requests for photographic evidence in an attempt to confirm who had been driving.
Lack, who denied failing to identify the driver on July 22 last year, apologised to the court, pointed out that both he and his partner had clean driving licences with no points, but that he genuinely did not know who was driving the car .
He added that he was in no way trying to wriggle out of anything.
Prosecutor Hilary Reece pointed out the first form of intended prosecution sent to Lack made it clear that if he had not been the driver, he ought to give details of anyone who might have been.
Magistrates told Lack he had failed to complete the notice of intended prosecution as requested and found him guilty.
No evidence was offered for the speeding offence and it was dismissed.
Lack, of Beamsley Close, Menston, was fined £1,050 and his licence endorsed with six penalty points. He was also ordered to pay £620 costs and a £105 victims surcharge.