What is the difference between an RFP, an RFQ, and an IFB?
An RFP asks vendors to propose how they would solve a complex requirement (evaluation considers price plus technical approach). An RFQ asks for a price quote on a fully defined need. An IFB is a sealed-bid solicitation where the lowest responsible bidder wins.
These are three different procurement solicitation types governed (at the federal level) by different sections of the Federal Acquisition Regulation. State and local agencies have analogous rules in their procurement codes.
An RFP (Request for Proposal) is used when the agency knows what outcome it wants but does not yet know how to get there. RFPs ask vendors to propose their technical approach, staffing model, management plan, and price. Evaluation considers both price AND non-price factors, and award goes to the proposal offering the "best value" (which is not necessarily the cheapest). Federal RFPs follow FAR Part 15. RFPs are the most common solicitation type for professional services, IT, consulting, and complex projects.
An RFQ (Request for Quotation) is used when the agency knows exactly what it needs and wants pricing on a specific product or service. Quotes from an RFQ are typically not binding offers — the agency reviews quotes and issues a purchase order to the chosen vendor. RFQs are governed at the federal level by FAR Subpart 13.3 (Simplified Acquisition Procedures) and are common for purchases below the simplified acquisition threshold (about $250K for most agencies).
An IFB (Invitation for Bid), also called an ITB (Invitation to Bid), is a sealed-bid solicitation. The agency provides detailed specifications and bidders submit sealed price bids. Award goes to the lowest responsive and responsible bidder — meaning the bidder who submitted the lowest price AND meets all responsibility criteria. There is no scoring of technical approach. Federal IFBs follow FAR Part 14, and they are common for construction and well-defined commodity purchases.
In short: RFP = "tell us how you would do this and what it costs." RFQ = "how much for exactly this?" IFB = "sealed bids, lowest qualified price wins."