Definition
The official seal of a corporation, adopted and maintained for the purpose of authenticating corporate acts and executing formal legal instruments. At common law, a corporation could only act, contract, or speak through its common seal — the seal was not merely evidence of authority but was the legal mechanism by which corporate intent was expressed. A document bearing the common seal was understood to carry the full authority of the corporate entity.
The common seal is distinct from a personal seal (used by an individual) and from a notarial or court seal. It belongs to the entity, not to any officer or agent of the entity.
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Common Language
Modern common usage (Wiktionary): The harbor seal, Phoca vitulina, a marine mammal found in northern Atlantic and Pacific waters.
Historical common usage (Webster's 1913): No relevant common-language sense; the term in general usage referred to the animal.
The gap here is complete. A researcher encountering "common seal" in a legal instrument or older corporate record should not be misled by the ordinary-language meaning. In legal sources the term has nothing to do with wildlife — it is a term of corporate and contract law referring to the authenticating seal of a legal entity.
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Common Confusion
COMMON SEAL vs. SEAL generally: Not all legal seals are common seals. A seal may be personal (affixed by an individual to a contract or deed), official (a government officer's seal), or notarial. The common seal is specifically the seal belonging to and representing a corporation or other artificial entity. Burrill's reference to corporations being able to "speak and act" only through their common seal captures the historical distinctiveness of the concept.
COMMON SEAL vs. CORPORATE FORMALITIES TODAY: Modern researchers sometimes treat the common seal as simply one corporate formality among many. Historically it was more than that — it was the legal voice of the corporation. The relaxation of the seal requirement, particularly in American jurisdictions, has eroded this distinctiveness, but the historical rule still controls the interpretation of older instruments.
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Why It Matters in Research
The common seal sits at the intersection of corporate law and contract law, and its significance shifted dramatically over two centuries. A researcher working with English sources prior to the nineteenth century will find the common seal treated as an absolute requirement for corporate action — instruments without it were void, not merely irregular. American law began diverging from this position early. By the time of Kent's Commentaries (cited by Burrill as 2 Kent's Com. 288–291), the rule had been substantially relaxed in the United States, and many states had either abolished the seal requirement by statute or rendered it presumptively unnecessary.
Traps in historical sources: An older instrument that recites "under our common seal" is signaling compliance with formal corporate authority — the presence or absence of this recital in historical records can determine whether a contract was enforceable against the corporate party at the time of execution. Do not read a historical instrument's seal clause through a modern lens.
Jurisdictional drift matters here: English sources will treat the common seal with greater formalism and for a longer historical period than American sources. Researchers moving between English and American materials on the same question need to track which rule governed at the time and place the instrument was made.
The corpus connection to contracts under seal is direct and important. The broader doctrine of contracts under seal — including the presumption of consideration, the extended limitations period in many jurisdictions, and the formal requirements — applies when a corporation acts by common seal. The entry on Contracts Under Seal and Statutory Substitutes in the Contracts & Commercial Law Encyclopedia provides the surrounding doctrinal framework.
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Historical Dictionary Support
The three source dictionaries agree on the core definition — the common seal is the seal of a corporation — but differ instructively in depth. Black's is functional and brief: the seal authenticates corporate acts and executes legal instruments. Bouvier's is the shortest, directing the reader to the broader SEAL entry, treating the common seal as a subtype rather than a standalone doctrine.
Burrill's is the most useful for research purposes. It provides the historical rule in its strongest form ("by which alone, at common law, it could speak and act"), cites to supporting authority (Davies' Reports and Dyer), and then immediately flags the erosion of that rule — both in England and in the American jurisprudence of Kent's era. This is the entry that gives the researcher the doctrinal arc rather than a static snapshot.
What the historical dictionaries collectively miss: they say little about the practical mechanics of the common seal (how it was kept, who had custody, what happened when the seal was affixed without proper authorization), and they do not address the transition period during which the seal requirement was being dismantled by statute in American states. Researchers working in that transitional period will need to consult state-specific statutory history.
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Jurisdictional Note
In England, the common seal requirement for corporate contracts was largely abolished by statute during the twentieth century, though many English companies retained seals as optional formalities. In the United States, the seal requirement for corporations was relaxed early and comprehensively, with most states eliminating mandatory seal requirements by statute well before the twentieth century. Researchers should identify the governing jurisdiction and the applicable date before drawing conclusions about whether a common seal was required for a given corporate act.
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Encyclopedia Cross-Reference
Contracts — Contracts Under Seal and Statutory Substitutes (The Law Mind Contracts & Commercial Law Encyclopedia)
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