bidder

A bidder is a person or organization that submits an offer in a bidding process with the aim of purchasing goods, services, or rights. Bidders participate in various settings, including auctions, procurement procedures, and digital marketplaces. In most contexts, bidders must meet eligibility criteria and comply with rules designed to ensure fair competition and transparency.

In auctions, bidders place bids that may advance in increments. The highest bid that meets any applicable reserve or terms at closing typically determines the winner. Some auctions use proxy bidding or hidden reserves; others may require payment, transfer of ownership, or delivery arrangements before the bid is considered final.

In procurement and construction markets, bidders respond to invitations to bid or proposals (ITB/ITP or RFP), presenting price and non-price information. A bid is evaluated against published criteria such as price, quality, delivery, and compliance with specifications. The contract is usually awarded to the bidder whose proposal offers the best value, subject to meeting mandatory requirements and post-qualification checks.

In digital advertising, a bidder may refer to an algorithm or system that participates in real-time bidding. Such bidders evaluate data signals, targeting criteria, and budgets to place competitive bids for individual ad impressions on behalf of a buyer. The winner is determined in microseconds by the auction mechanism of the platform.

Ethical and legal considerations include prohibitions on bid rigging and other forms of collusion in many jurisdictions, as well as requirements for disclosure, transparency, and integrity in public procurement. Violations can lead to penalties, contract voidance, and debarment.