The 67-year-old singer and his 52-year-old partner have invited 50 of their friends and family - including the likes of David and Victoria Beckham, Elizabeth Hurley and Ozzy and Sharon Osbourne - to their home in Windsor, Berkshire, South East England, for the ceremony on December 21.
A friend explained: ''Elton and David have been planning this for months.
''Elton is flamboyant but, for once, this will be decidedly low-key affair. Only close friends and family are invited - it's going to be a small, intimate do.''
The couple - who have been together for 21 years and exchanged vows in a civil partnership ceremony in 2005 - are planning for their two sons, Zachary, three, and Elijah, 23 months, to be ringbearers during the ceremony.
The source told the Daily Mirror newspaper: ''It's important to David and Elton the boys play a special part.''
Guests at the ceremony will be treated to festive-themed canapes and mulled wine.
It only became legal to convert civil partnerships in to marriage two days ago and the couple's wedding promises a much different affair to that they staged nine years ago, which featured 650 guests, including Lulu and Ringo Starr.
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