Definition
A term of art appearing in the execution clauses of deeds, indentures, leases, and other instruments executed in duplicate, signifying that each party has signed the copy delivered to the other party. The word carries a precise procedural meaning: not merely that all parties have signed, but that an actual physical exchange of signed copies has taken place. When parties to an indenture affix their signatures and seals "interchangeably," each holds a counterpart bearing the other's hand and seal, creating reciprocal written evidence of the agreement.
Common Language
Modern common usage (Wiktionary): With the ability of being interchanged or swapped.
Historical common usage (Webster's 1913): In an interchangeable manner; by interchange; alternately.
The everyday sense of "interchangeably" suggests functional equivalence or substitutability between things. The legal term carries a narrower, procedural meaning tied specifically to the execution of duplicate instruments — it does not merely mean the parties signed equivalent documents, but that they physically exchanged signed copies. A researcher encountering this word in a modern contract or correspondence might read it as a statement of equivalence; in historical legal instruments, it is a statement about a completed act of exchange.
Common Confusion
"Interchangeably" is sometimes read as a mere formality or filler language in closing attestation clauses, when in fact it conveyed substantive procedural information. In the era of handwritten indentures, the interchange of signed counterparts was the act that completed the transaction and established each party's proof of the agreement. Treating the term as decorative risks misreading whether a historical instrument was properly executed.
The word should also not be conflated with "alternatively" or "jointly." Burrill notes the Latin equivalentis alternatim, but "interchangeably" implies simultaneous mutual delivery of counterparts, not sequential or joint signing of a single document.
Why It Matters in Research
Researchers working with pre-twentieth-century deeds, indentures, or lease agreements will encounter "interchangeably" almost exclusively in the testimonium or attestation clause — the closing recital beginning "In witness whereof, the parties have hereunto interchangeably set their hands and seals." Recognizing the term as a signal of duplicate-counterpart execution is essential for understanding the physical form the instrument took and how many signed copies should exist in the record.
In archival and title research, the presence or absence of this word can indicate whether an instrument was understood to have been executed in a single original or in exchanged counterparts. When searching for a complete chain of title or the full execution record of a historical lease, the term is a practical clue: look for the counterpart.
The term has almost entirely disappeared from modern drafting, displaced by "counterparts" clauses and electronic execution frameworks. Researchers should not expect to find "interchangeably" in instruments drafted after the mid-twentieth century, and its absence from modern sources can create a false impression that the concept itself is obsolete — the practice of counterpart exchange persists, only the vocabulary has changed.
Because Black's second edition cites Roosevelt v. Smith (a New York Miscellaneous Reports case from the late nineteenth century) as illustrative authority, researchers tracing the doctrinal treatment of this term in case law should look to state court decisions construing indenture execution formalities, particularly in jurisdictions with strong real property recording traditions.
Historical Dictionary Support
All four source dictionaries converge on the same core definition: execution by exchange of signed counterparts in duplicate instruments. The agreement across Black's (both editions), Bouvier, and Burrill is unusually tight, suggesting this was a settled term of art with little interpretive controversy.
Burrill adds the most texture, supplying the Latin equivalent alternatim and identifying the precise attestation formula in which the term appeared ("In witness whereof, the said parties have hereunto interchangeably set their hands and seals"). Burrill also emphasizes that the term imports both execution by all parties and actual interchange — the physical exchange being the operative act, not merely the signing.
Black's second edition is the only source to cite judicial authority, referencing Roosevelt v. Smith for the proposition about counterpart signing. The first edition of Black's and Bouvier reproduce nearly identical text without citation, a common pattern for terms whose meaning was treated as self-evident by the late nineteenth century.
None of the historical dictionaries address what consequences, if any, followed from omitting the word from an attestation clause, or whether an instrument lacking the term but executed in counterparts would be treated differently. Researchers with questions about the legal effect of defective execution formalities will need to look beyond dictionary sources to treatises on conveyancing and real property.
Jurisdictional Note
The term appears most frequently in English and American common law instruments following English conveyancing practice. American usage tracked English forms closely through the nineteenth century. No significant jurisdictional split in the meaning of the word itself has been identified, though the underlying formalities of deed and indenture execution varied by state.