An expert is an independent person specialised in a particular field who can assist an auction house in authenticating and valuing certain items. The Conseil des Ventes Volontaires has set up an accreditation scheme for experts who wish it.
The seller may use the expert of their choice. Otherwise, auction houses regularly work with the same experts; if they are employed by the auction house, they are known as specialists.
French law no. 2004-130 of 11 February 2004 stipulates that the expert and the auctioneer are jointly and severally liable. The limitation period is five years from the date of sale.