RFP vs RFQ vs IFB: what each solicitation means and how to respond

The three acronyms look interchangeable, and in conversation people use them loosely. In federal contracting they are different procedures with different rules, and each one changes what a winning response looks like. This guide sets them side by side, explains the notices that come before them, and lists what to do differently for each.

The short version

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Before the solicitation: RFIs and sources sought

Requests for information. Agencies use RFIs to learn about the market before they decide how to buy. Under FAR 15.201(e), an RFI may be used when the government does not yet intend to award a contract, and responses are not offers. Formal RFIs are one of the market research techniques listed in FAR 10.002(b)(2).

Sources sought. This is a SAM.gov notice type, not a defined FAR procedure. Agencies use it to find out whether capable businesses exist, often to decide whether to set the work aside for small business. If you are a small business and want the work set aside, this is the moment to say so, with evidence.

Presolicitation notices. For most actions over $25,000, the agency must publish a synopsis on SAM.gov (FAR 5.101(a)(1)), normally at least 15 days before it issues the solicitation (FAR 5.203(a)). Commercial buys can use a shorter period or a combined synopsis and solicitation.

How to answer an RFI or sources sought notice:

• Answer the questions asked, in the format asked, and keep it short. Capability, relevant past work, socioeconomic status and contract vehicles are what the agency is screening for.
• Point out anything in the draft requirement that would block competition or drive up cost. That is the main reason agencies ask.
• Don't send pricing unless it is requested, and mark anything proprietary.
• Put the notice number in your tracker. When the solicitation comes out, it will often reference it.

IFB: sealed bidding

Sealed bidding is defined in FAR 14.101: competitive bids, a public bid opening, and award on price. The agency prepares and publicizes the IFB, bidders submit sealed bids, the bids are evaluated without discussions, and the contract goes to the bidder whose conforming bid is most advantageous to the government, considering only price and price-related factors (FAR 14.408-1(a)).

When is it used? Under FAR 6.401(a), sealed bids are the method when four things are true: time permits, award will be on price and price-related factors, discussions aren't needed, and more than one bid is reasonably expected. That is why IFBs are common for construction with complete drawings and for well-specified supplies. The contract must be firm-fixed-price, or fixed-price with economic price adjustment (FAR 14.104).

What it means for you:

• Responsiveness is everything. A bid must comply in all material respects with the IFB (FAR 14.301(a)). A bid that fails to conform to the essential requirements, or that adds your own conditions, is rejected (FAR 14.404-2). An exception in a cover letter, a changed delivery date, or a missing amendment acknowledgment can sink an otherwise low bid.
• No second chance to improve. There are no discussions, so you can't fix a weak bid after opening. You can only correct genuine mistakes through the process in FAR 14.407, which is narrow and needs evidence.
• Bids are opened in public. The contracting officer opens all bids publicly and reads them aloud where practical (FAR 14.402-1). Your price becomes known to your competitors.
• Late means out. A late bid is generally not considered unless it arrives before award, won't unduly delay the acquisition, and meets one of the narrow exceptions, such as proof that it was already under the government's control in time (FAR 14.304(b)).
• Responsibility is checked separately. Winning on price still requires the contracting officer to find you responsible: able to perform, with the money, capacity and record to do it.

Two-step sealed bidding (FAR 14.501) is a hybrid used when adequate specifications aren't available. In step one you submit an unpriced technical proposal, which is judged acceptable or not. In step two, only the acceptable offerors submit sealed priced bids.

The IFB forms you will see are SF 33, SF 26 and SF 1447 (FAR 14.201-1), and SF 1442 for construction (FAR 36.701).

RFP: negotiated acquisition

An RFP is the tool for negotiated acquisitions (FAR 15.203(a)). At a minimum it describes what is being bought, the terms, what your proposal must contain, and the factors and subfactors that will be used to evaluate it, with their relative importance. In the uniform contract format those last two items are Section L (instructions) and Section M (evaluation factors); our guide to Section L vs Section M covers them in detail.

The basis of award is the first thing to find:

• Best value tradeoff (FAR 15.101-1): the agency can award to a higher-priced proposal if its strengths are worth the difference.
• Lowest price technically acceptable (FAR 15.101-2): the non-price factors are pass or fail, tradeoffs aren't permitted, and the lowest-priced acceptable proposal wins.

What makes an RFP different from an IFB:

• Your proposal is scored, not just checked. Compliance gets you into the evaluation; the strength of your answer against Section M decides the result.
• Discussions may happen, or may not. The agency can establish a competitive range and hold discussions with the offerors in it, then ask for final proposal revisions (FAR 15.306, 15.307). But if the solicitation says so, it can award on initial proposals without discussions (FAR 52.215-1(f)(4)), and most do. Write your first proposal as if it is your only one.
• Proposals stay private. There is no public opening, and you get a debriefing rather than a bid tabulation.
• Late proposals follow rules much like late bids, with a 4:30 p.m. local time default if the RFP doesn't set a time (FAR 15.208).

Commercial buys under FAR Part 12 often use an RFP built around the SF 1449, where the provisions at 52.212-1 and 52.212-2 do the job of L and M.

RFQ: simplified acquisition and schedule orders

RFQs are used most often for purchases under the simplified acquisition threshold, which has been $350,000 since October 1, 2025, and the micro-purchase threshold is $15,000 (FAR 2.101, table of effective dates). Simplified procedures can also be used for commercial products and services up to $9 million (FAR 13.500).

What is different about an RFQ:

• A quotation is not an offer. Under FAR 13.004(a), the government can't accept your quotation to form a contract. Its order is the offer, and the contract forms when you accept it, in writing or by starting the work. In practice it means you can be asked to confirm your price and terms before the order is issued.
• Lighter evaluation. The agency doesn't have to use the formal procedures of Parts 14 and 15. It needn't write a formal evaluation plan, set a competitive range, hold discussions or score quotations (FAR 13.106-2(b)). It must still tell you the basis for award (FAR 13.106-1(a)(2)) and evaluate on that basis.
• Small business set-asides. Purchases above the micro-purchase threshold and up to the simplified acquisition threshold are set aside for small business when the agency expects offers from two or more responsible small businesses at fair prices (FAR 19.502-2(a)).
• Fast deadlines. RFQs often allow days, not weeks. A two-page response that answers every instruction beats a polished one that misses the cut-off.
• GSA Schedule orders are RFQs too. Agencies ordering from Federal Supply Schedules send an RFQ to schedule holders, usually through GSA eBuy (FAR 8.405-1). You need to hold the schedule, and your quote has to fit within your schedule pricing and terms.

The standard form for a simple RFQ is the SF 18 (FAR 13.307); commercial RFQs often use the SF 1449.

The FAR is being rewritten: what that means here

Since 2025 the federal government has been rewriting the FAR under the Revolutionary FAR Overhaul. Agencies have adopted model deviation text for most parts, while the formal rule changes were still at the proposed stage as of October 2026. The deviation text renumbers Parts 13, 14 and 15. It moves commercial RFQs into Part 12, and adds two new award approaches to Part 15. It also says "negotiations" where the old text said "discussions", and sealed bidding stays a price-only method.

For a bidder, the practical point is simple. The concepts in this guide carry over, but the section numbers in your solicitation may not match the ones here. Cite what your solicitation cites, and if it references a deviation, read that version on acquisition.gov.

What changes in how you respond

State and local solicitations use the same ideas under other names: an invitation to bid (ITB), request for bids (RFB) or IFB is usually low-price sealed bidding, and an RFP is usually scored. The rules come from the state or city procurement code, not the FAR, so read the instructions to bidders closely.

A checklist for any solicitation

1. What type is it, and what is the basis for award? Find the sentence, don't infer it.
2. Is your response an offer, and how long must you hold it open?
3. What are the pass or fail requirements: forms, certifications, registrations, bonds, amendments?
4. What format, page limits and file rules apply?
5. When and how do you submit, in what time zone, and what happens if you're late?
6. When are questions due, and where will answers and amendments be posted?
7. Is it set aside, and do you qualify on the date of your offer?

Every one of those answers belongs in a compliance matrix, with the page it came from. Our guide to building an RFP compliance matrix shows how, and how to shred an RFP gives a reading order.

Get the matrix from the PDF

Whether it's an IFB, an RFP or a long RFQ, the work is the same: find every instruction, requirement, form and deadline before you write. FileAI's RFP compliance matrix does that from your solicitation files for US$99 per RFP. Each instruction, evaluation factor, form, eligibility condition and deadline comes with its quote and page. Try the free preview first.

Sources

• Federal Acquisition Regulation: 2.101 Definitions (thresholds), 5.101 and 5.203 (publicizing), 6.401 (sealed bidding and competitive proposals), 10.002 (market research)
• FAR Part 13: 13.004, 13.106-1, 13.106-2, 13.307, 13.500
• FAR Part 14: 14.101, 14.104, 14.201-1, 14.301, 14.304, 14.402-1, 14.404-2, 14.407-1, 14.408-1, 14.501
• FAR Part 15: 15.101-1, 15.101-2, 15.201, 15.203, 15.208, 15.306, 15.307, 52.215-1
• FAR 8.405-1 (schedule orders), 19.502-2 (set-asides), 36.701 (construction forms)
• Acquisition.gov, Table of effective dates for the MPT and SAT and the FAR Overhaul part deviation guide

This guide is general information, not legal or procurement advice. FAR citations are to the official FAR on acquisition.gov as of October 2026 (FAC 2026-01); agencies using FAR Overhaul deviations may cite different section numbers. Always follow the instructions in the solicitation you're responding to.