If there is one fundamental misunderstanding within auction-related law, it is when (or if) an auctioneer may legally reopen the bidding after saying, “Sold!” For the most part, the answer to the question, “Can auctioneers reopen the bidding?” is “Legally, they cannot.”
As we have noted before, auctioneer bid calling is a series of oral contracts. A bid is received from a bidder and is accepted by the auctioneer on behalf of the seller. In a without reserve auction, this oral contract is contingent upon the auctioneer not receiving a higher bid, and the bidder not retracting his bid. In a reserve auction, a third contingency is present, which is that the seller not withdraw the item.