The Queen and Duke of Edinburgh are continuing to recover from heavy colds which prevented them from travelling on Wednesday to a Christmas break in Norfolk.
The Queen and Philip were expected to travel from London to King's Lynn by train and then on to their nearby private Sandringham estate.
But a Buckingham Palace spokesman said on Wednesday: "The Queen and the Duke of Edinburgh have heavy colds, and so have decided not to travel to Sandringham today."
On Tuesday it was announced that the Queen would be stepping down as patron from 25 national organisations at the end of her 90th birthday year, with the patronages passing to other members of the Royal Family.
The move is likely to be seen as a common-sense decision which acknowledges the Queen's advancing years but Buckingham Palace stressed the monarch is still patron of around 600 organisations.
The Queen and Duke, 95, were surrounded by their family on Tuesday when they hosted their annual Christmas lunch for dozens of relatives at Buckingham Palace.
Despite their advancing years, the couple appear to remain in good health and have missed few official engagements in recent years due to illness.