Direct comparison
Sole Source vs. Single Source
Sole source vs. single source procurement, explained: the market-exclusivity vs. business-choice distinction, and how 2 CFR 200.320 and FAR treat each.
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Side-by-side comparison
| Dimension | Sole Source | Single Source |
|---|---|---|
| What it means | Only one supplier exists in the market capable of providing the required good, service, or equipment — a factual, market-based determination, not a preference. | More than one supplier could technically provide the item, but the purchaser chooses to buy from just one, without soliciting competing offers. |
| Why competition is skipped | Competition is impossible — no second qualified source exists (patented equipment, sole manufacturer, unique proprietary expertise). | Competition is possible but not pursued — commonly for standardization with existing equipment, compatibility, warranty/service continuity, or an existing schedule agreement. |
| Regulatory basis (federal grants) | 2 CFR §200.320(c)(3): the item is "available only from a single source" — one of four permitted grounds for a noncompetitive proposal. | Not a separate 2 CFR 200 category — treated as the same noncompetitive-proposal method, so it must still satisfy one of §200.320(c)'s four allowable grounds to be an allowable cost. |
| Federal contracting (FAR) treatment | FAR Part 6 sole-source award requires a Justification for Other Than Full and Open Competition (JOFOC/J&A) under FAR 6.302. | FAR does not define "single source" as a standalone term; the closest analog is a "limited sources" justification for Federal Supply Schedule orders (FAR 8.405-6), exempt from the full Part 6 JOFOC process. |
| Documentation burden | Typically higher — must show market research proving no other source exists (vendor survey, patent search, manufacturer confirmation). | Typically framed as programmatic/technical justification for why compatibility or standardization outweighs competing the purchase; a price-reasonableness determination is still required. |
| Common trigger in a lab/research setting | A proprietary reagent, instrument, or software licensed by only one manufacturer with no functional equivalent. | An add-on module, part, or consumable that must be compatible with existing capital equipment already on-site, from among several vendors who could otherwise compete. |
| Audit risk if misclassified | Calling something sole source when competitors actually exist is a common audit finding; reviewers expect documented market research supporting the claim. | Calling something single source without tying it to one of §200.320(c)'s allowable grounds risks the purchase being disallowed as an unallowable cost. |
| Everyday usage | Used loosely, and often interchangeably with "single source," in casual conversation and some institutional policies. | Same — institutional purchasing policies vary; some use "single source" as their formal term for the standardization/compatibility scenario specifically, others use it as a synonym for sole source. |
Common questions
FAQ
Are "sole source" and "single source" legally the same thing under federal grant rules?+
For compliance purposes, largely yes — both are documented as a "noncompetitive proposal" under 2 CFR §200.320, the fifth allowed procurement method, and both must satisfy one of the same four allowable grounds in §200.320(c). The terms describe different reasons a purchase might qualify (market exclusivity vs. a standardization/compatibility decision), but neither creates a separate regulatory category from the other under the Uniform Guidance.
Does my institution need a different form for a single-source purchase than a sole-source purchase?+
Not under federal Uniform Guidance — both route through the same noncompetitive-procurement justification and documentation requirement. Some institutional purchasing policies do distinguish the two administratively, for example a lighter-weight single-source form for standardization purchases below a dollar threshold versus a full sole-source justification above it. Check your own institution's procurement policy: 2 CFR 200 sets a compliance floor, and many universities and hospitals layer stricter internal rules on top.
Where can I find a template for writing the justification itself?+
See CASRAI's guide to the sole-source justification letter for required elements and a worked example. This comparison page focuses on the distinction between the two terms; that guide covers the format of the document you would actually produce once you've determined which route applies.
What is a "sole source agreement"?+
An informal term for the contract or purchase order that results once a sole-source (noncompetitive) procurement has been justified and approved. It is not a distinct legal instrument from an ordinary contract — only the procurement method that led to it skipped competition. The same contract-provisions requirements under 2 CFR §200.327 still apply regardless of how the source was selected.
Going deeper
