According to an official press release delivered by Kensington Palace on Sept. 12:
His Royal Highness The Duke of Cambridge is to leave operational service in the Armed Forces.
He completes his Tour with the Royal Air Force Search and Rescue Force at RAF Valley, Anglesey, after more than seven-and-a-half years of full-time military service.
After ending his tour, Prince William and his family will be moving to Kensington Palace. The press release explained:
The Duke and Duchess of Cambridge and Prince George are expected to move into their official residence at Kensington Palace within the next few weeks.