A referential bid is a bid or tender for the purchase or supply of goods or services whose value is stated by reference to the bids or tenders received from competitors (if any), e.g. "such a sum as will exceed by £200 the amount ... offered ... by any other proposing purchaser".[1] Case law in various jurisdictions (see below) has generally ruled that referential bids frustrate the purpose of sealed competitive bidding and are therefore unfair.[2]