Charles and Camilla are expected to be joined by the Prince and Princess of Wales and their children Prince George, Princess Charlotte and Prince Louis for morning service at St Mary Magdalene Church.
The King and Queen, along with the Princess Royal and her husband Vice Admiral Sir Timothy Laurence, waved to well-wishers while attending a Christmas Eve service at the church on Sunday.
Royal Christmases traditionally feature the greeting of people outside the church, and a family lunch with turkey and all the trimmings.
Royal Christmases traditionally feature the family greeting people outside St Mary Magdalene Church. (AP PHOTO)
Sandringham House has been the private home of four generations of British monarchs for more than 160 years, and now belongs to the King.
Charles's second Christmas message as monarch will be broadcast in the UK at 3pm on Monday.
The message was recorded in the Centre Room in Buckingham Palace which leads on to the royal residence's iconic balcony.
The room is decorated with a living Christmas tree which will be replanted after the broadcast.
From its branches hang natural and sustainable decorations including hand-turned wood, dried oranges, glass baubles, pine cones and paper.
Charles, like Queen Elizabeth II, writes his Christmas broadcasts and last year he followed his mother's well-established template, a personal reflection on the year, touching on current issues and with a Christian framework.
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