"After careful consideration, the Duke of Edinburgh made the decision to voluntarily surrender his driver's license," the palace said in a statement.
Later, the prince apologized to Emma Fairweather, who suffered a broken arm in the collision, blaming the crash on the sunlight that hid her eyesight and admitting that the incident had "shaken" her.
"I have crossed that crossing several times and I know very well how much traffic that main road uses," wrote the Duke of Edinburgh, blaming the incident on the bright sunlight.
The accident left the duke's car turned over on its side, and a witness then told the Press Association that he helped get a bloody Philip out of the vehicle.
She told the newspaper after receiving the letter: "I thought it was very good for him to sign as 'Philip' and not as a formal title, I was pleasantly surprised by the personalized nature."
The incident dominated the British media and led to a public debate over whether people over a certain age should have to retake their driving tests.
CNN's Max Foster contributed to this report.