A reverse auction is a type of auction in which the roles of buyer and seller are reversed. In an ordinary auction (also known as a forward auction), buyers compete to obtain a good or service by offering increasingly higher prices. In a reverse auction, the sellers compete to obtain business from the buyer and prices will typically decrease as the sellers undercut each other.
A reverse auction is similar to a unique bid auction as the basic principle remains the same, however a unique bid auction follows the traditional auction format more closely as each bid is kept confidential and one clear winner is defined after the auction finishes.
In business, the term most commonly refers to a specific type of auction process (also called procurement auction, e-auction, sourcing event, e-sourcing or eRA, eRFP, e-RFO, e-procurement, B2B Auction) used in government or private sector procurement.
In consumer auctions, the term is often used to refer to sales processes that share some characteristics with auctions, but are not necessarily auctions.