The A-list couple recently sold their Hertfordshire mansion, which they bought in October 1999 for £2.5 million, and are now preparing to set up home in a £45 million, four-storey London townhouse in the capital.
But before they 'downsize', they have decided to get rid of some of their prized possessions from the Grade II listed building, real name Rowneybury House.
"After deciding to sell Beckingham Palace, David and Victoria realised there was no way they could fit all their belongings into one, smaller pad," a source told the Daily Mirror.
"They have shipped a few treasured items to California and given some things to their families, but there is still loads left.
"Victoria had the brilliant idea to sell it off for charity and now wants to host a massive auction at Beckingham Palace.
"The house has been the scene of many fund-raising dos – the World Cup party, her 'full length & fabulous' ball, children's tea parties and so forth – so why not host a farewell auction there too? There will be some amazing stuff for sale so she hopes to raise thousands."
The lots reportedly up for grabs will include kitchen items, household appliances, designer clothes, and even the famous gold thrones that featured in their 1999 wedding ceremony.
The couple have already had some of their things delivered to their new home in the capital, after reportedly signing the contract last Friday.
Victoria's designer friend Kelly Hoppen is said to have cast her expert eye over the property and given it a makeover ahead of the moving in date.