An RFI asks for information and is not a bid. An RFQ asks for prices, usually for simpler or smaller purchases. An IFB, also called an invitation to bid, asks for sealed prices on clearly defined work, and the lowest responsive, responsible bidder usually wins. An RFP asks for proposals, and the buyer weighs price together with quality, approach and experience.
RFI: request for information
An RFI is research. The buyer wants to learn what solutions exist, what they might cost in general terms, and who can provide them. There is no award. Your answer may still shape the later solicitation, so a clear, helpful response is worth the time.
Keep it short, answer the questions asked, and avoid sharing anything you would not want a competitor to read, since responses may become public.
RFQ: request for quotation
An RFQ asks for a price on a defined product or service. Buyers often use it for smaller or simpler purchases, sometimes with a shorter timeline and fewer forms. The award usually goes to the lowest acceptable quote, though some RFQs also consider delivery time or other factors.
In federal buying, a quote is generally not a binding offer until an order is issued and accepted. Other buyers treat quotes differently, so read the terms.
IFB: invitation for bids
An IFB, sometimes called an ITB or RFB, is used when the buyer can describe the work completely and price is the deciding factor. Bids are sealed and usually opened in public at a set time. The award goes to the lowest bidder whose bid meets every requirement and who is judged able to perform.
There is normally no negotiation. A missing form, signature or addendum acknowledgment can get a bid rejected even when its price is lowest.
RFP: request for proposals
An RFP is used when the buyer wants to compare approaches, not just prices. You write a proposal that explains how you will do the work, who will do it, and what it will cost. Evaluators score proposals against published criteria, and the buyer may hold discussions or ask for revised offers before award.
A related form is the request for qualifications, used for some professional services such as architecture and engineering, where firms are ranked on qualifications first and price is negotiated afterward.
How to tell which one you have
Names vary between agencies, so look past the title. Check these points instead.
- The evaluation section: price only, or price plus other factors?
- Whether the buyer may negotiate or ask for revised offers.
- Whether bids are opened publicly at a set time.
- What you must submit: a price form only, or a full written proposal.
Why the difference matters
The type of request changes how you spend your effort. On an IFB, accuracy and a sharp price matter most, and polished writing earns nothing. On an RFP, a clear plan, strong references and direct answers to each evaluation factor can outweigh a small price gap. On an RFI, the goal is to be useful and memorable before the real competition starts.
The type also affects what happens after award. IFB results are usually public at the opening, so you learn quickly where you stood. RFP results take longer, and losing bidders may be able to ask for a debriefing to learn how they were scored.
Rules vary by agency and state; check the solicitation and your own advisers.
Common questions
Can an RFI lead to an RFP?
Yes. Buyers often use RFI responses to write a later RFP or IFB. Responding can help you understand the need early.
Can I negotiate on an IFB?
Generally no. An IFB is awarded on the sealed prices as submitted, so your first price is your only price.
Is an RFQ always smaller than an RFP?
Usually, but not always. The method depends on the buyer's rules and how clearly the need can be defined.