RFQ: An RFQ (request for quote) is a buyer's formal request asking one or more suppliers to price a defined part or job, usually with drawings, quantities and a reply deadline.
An RFQ is how most custom manufacturing has been bought for decades. The buyer sends a package (CAD files, drawings, material, quantity, tolerances, delivery date) to a few suppliers and asks each to reply with a price and a lead time by a set date. The buyer then compares the answers and awards the work.
Example: a buyer sends an RFQ for 200 aluminium housings to four shops on a Monday and asks for replies by Friday. Each shop’s estimator spends an hour or two working out the cost, and three of the four will not win the job.
That last point is the hidden cost of the RFQ process: estimating time is spent on every request, but only some turn into orders. Your win rate tells you how much of that effort pays.
People sometimes use RFQ and RFP (request for proposal) as if they meant the same thing. An RFQ asks for a price against a fixed specification; an RFP invites the supplier to propose how to do the work. An RFQ is also different from an instant quote, where software returns the price while the buyer waits.
For how to run the process well on the supplier side, see the RFQ process.
Go deeper: The RFQ process in manufacturing, from request to purchase order