British media reported the pair were seen arriving at RAF Northolt,a military base outside London,on Tuesday morning London time when they boarded a flight to Aberdeen.
The couple is thought to have gone to Balmoral,where the Queen spent her final weeks before she died aged 96 on September 8. Members of the royal family had rushed to Scotland earlier that day after doctors became concerned for her health.
He is likely to stay at Birkhall,his residence on the estate that he inherited from the Queen Mother in 2002.
Although the period of national mourning ended after the Queen’s funeral,royal mourning lasts for an additional seven days. Members of the family are not expected to carry out official engagements and flags at royal residences will stay at half-mast.
Once the mourning period is over,there will be a phased period back to working life – starting with military or charity engagements,before working members of the royal family continue with their personal projects and causes.
Buckingham Palace has declined to comment on the King’s private time.
Charles III is expected to follow a precedent established by Queen Victoria in 1837 and keep Buckingham Palace as his official London residence,The Times reported.