Definition
An intermediary is a person or entity that stands between two other parties and facilitates dealings between them. The intermediary acts as a go-between — communicating, negotiating, or transacting on behalf of, or in connection with, both sides of a relationship, without necessarily being a full party to the underlying transaction.
The term carries specific legal weight across several distinct contexts:
1. General agency/commercial law. An intermediary negotiates or arranges a transaction between two principals. In this role the intermediary is typically treated as the agent of both parties for limited purposes — bound to transmit information accurately and to act in the interest of completing the arrangement without favoring one side. Black's Law Dictionary (2nd Ed.) identifies this figure with the civil-law broker and notes that Louisiana's Civil Code characterized such a person as the mandatary of both parties.
2. Products liability — learned intermediary. In tort law, a "learned intermediary" is a sophisticated professional — most commonly a licensed physician — who stands between a product manufacturer and the end consumer. The doctrine holds that a manufacturer's duty to warn runs to the learned intermediary rather than directly to the patient or consumer, provided the intermediary has the expertise to evaluate the risk and is expected to exercise independent judgment in passing the product along.
3. Tax law — qualified intermediary (QI). In the context of IRC § 1031 like-kind exchanges, a "qualified intermediary" is an independent third party who facilitates the deferred exchange by acquiring the relinquished property from the taxpayer, holding the exchange proceeds, and transferring the replacement property. The QI's role is procedurally essential: taxpayer receipt of funds before the exchange closes collapses the tax deferral.
4. Financial regulation. "Intermediary" broadly describes any regulated entity — bank, broker-dealer, insurance company — that stands between capital providers and capital users, channeling funds or risk. This usage is largely descriptive rather than a term of art with a single fixed definition.
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Common Language
Modern common usage (Wiktionary): "That intermediates." (i.e., one that mediates or acts between parties.)
Historical common usage (Webster's 1913): An adjective meaning "lying, coming, or done, between; intermediate." Webster's treats the term primarily as a modifier, not a noun describing a legal actor.
The common-language sense captures the spatial or relational idea of "being in the middle" but misses the legal consequences that attach. In law, the intermediary's position generates specific duties, liabilities, and sometimes protections (as with the learned intermediary doctrine) that have no analog in ordinary usage.
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Common Confusion
INTERMEDIARY vs. AGENT. Every intermediary exercises some agency function, but not every agent is an intermediary. An agent typically represents one principal; an intermediary, at least in the civil-law tradition Black's reflects, is understood to stand between two principals simultaneously. The distinction matters when analyzing fiduciary duties: a pure agent owes loyalty to one principal, while an intermediary's dual position creates more limited and symmetrical obligations.
INTERMEDIARY vs. BROKER. The terms overlap substantially — Black's 2nd Ed. equates the intermediary with a broker in civil-law usage. In modern regulatory contexts, however, "broker" carries licensing requirements and statutory definitions that do not automatically attach to the broader term "intermediary." Researchers should not assume that a document using "intermediary" in a historical source is describing a licensed broker in the modern regulatory sense.
LEARNED INTERMEDIARY vs. QUALIFIED INTERMEDIARY. These are unrelated legal constructs that share only the modifier. The learned intermediary is a tort doctrine about the chain of warning duties in products liability. The qualified intermediary is a tax-compliance role in IRC § 1031 exchanges. Conflating them in research is an easy error when searching broadly on "intermediary" across practice areas.
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Why It Matters in Research
The term "intermediary" is a trap for broad-corpus searchers precisely because it is not a single legal concept — it is a relational description that different bodies of law have adopted and defined independently. A search returning all uses of "intermediary" across the Law Mind corpus will surface tort cases applying the learned intermediary doctrine, tax materials on QI requirements, securities regulation materials on financial intermediaries, and historical civil-law sources about brokers. These sources do not speak to each other.
For historical sources specifically: Black's 2nd Ed. grounds the term almost entirely in civil-law and Louisiana codifications. Common-law jurisdictions of the same period often used "broker," "factor," or "agent" where civil-law writers used "intermediary." A researcher working with pre-twentieth-century common-law materials should not expect "intermediary" to appear as a term of art — look instead for functional equivalents.
The learned intermediary doctrine developed substantially in the second half of the twentieth century and will not appear in any historical dictionary source. Black's 2nd Ed. contains no reference to it. Researchers should treat products liability materials as an entirely separate corpus from the historical definitions.
For 1031 exchange research, the qualified intermediary role is a creature of Treasury regulations (Treas. Reg. § 1.1031(k)-1), not common law. The term is defined precisely in that regulatory context, and historical dictionary definitions are of no practical use.
Jurisdictional variation in the tort context is meaningful: a minority of jurisdictions recognize a "direct-to-consumer" exception to the learned intermediary doctrine (most prominently applied to mass-market direct-to-consumer pharmaceutical advertising). Researchers should not assume the doctrine operates uniformly across states.
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Historical Dictionary Support
Black's Law Dictionary (2nd Ed.) defines intermediary narrowly as a civil-law concept — a broker employed to negotiate between two parties, treated as the mandatary (agent) of both. The entry cites Louisiana's Civil Code of 1900, anchoring the definition in a jurisdiction that follows the civilian tradition. This reflects the term's continental origins; in French and Spanish civil law, the intermédiaire or intermediario was a recognized commercial figure with defined obligations to both contracting parties.
Black's definition, while concise, captures the most important structural feature: the intermediary's dual-mandate status. Because both parties look to the intermediary, the intermediary cannot take strongly adversarial positions in favor of either. This distinguishes the role from a standard agent, whose loyalty runs in one direction.
What Black's 2nd Ed. does not capture — because these developments postdate the edition — is the dramatic expansion of "intermediary" into tort law (learned intermediary), tax compliance (qualified intermediary), and financial regulation. Modern practitioners reading Black's 2nd Ed. would receive a historically accurate but practically incomplete picture of the term's current reach. Researchers using this source alone should treat it as establishing the baseline civil-law meaning, not as authority on contemporary usage.
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Jurisdictional Note
The learned intermediary doctrine is recognized in most U.S. jurisdictions but is subject to a direct-to-consumer advertising exception in a minority of states, meaning the doctrine does not shield a pharmaceutical manufacturer when it advertises directly to patients rather than through prescribing physicians. The qualified intermediary requirements for IRC § 1031 exchanges are federal, but state tax treatment of like-kind exchanges varies and should be checked separately.
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Encyclopedia Cross-Reference
The Law Mind Torts & Personal Injury Encyclopedia: Products Liability — Learned Intermediary Doctrine
The Law Mind Real Estate Transactions & Construction Encyclopedia: 1031 Like-Kind Exchanges — Identification Rules, Timing, Qualified Intermediaries, and Boot
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