The firm in Battersea, south London, will try the new format in a timed online-only book sale after Easter.
Owner Stephan Ludwig said the trial was “partly in response to recent Advertising Standards Authority guidelines” but he had been looking at providing buyers with premium-inclusive fees for a couple of years.
He added: “I am a strong proponent of transparency. On these sales, the price you bid will be the price you pay.
“While the ASA guidelines are only guidelines, there is a requirement to avoid the consumer being surprised. There should be an acceptance that charges should be made clear to the consumer.”
Forum currently hosts two or three timed online auctions a month and has plans to increase this to five or six.
Auctioneers have been trialling different ways of displaying fees in advance of the March compliance deadline. Norfolk sporting guns specialist Holt’s now displays a buyer’s premium calculator under each lot in its online catalogue.
ATG parent Auction Technology Group, after discussions with the Committee of Advertising Practice, has issued advice to clients on p48-49.