Definition
Two or more persons appointed to hold and administer property as trustees for the benefit of one or more beneficiaries. Joint trustees share a single office — they are not separate trustees acting in parallel, but co-holders of one fiduciary position. As a general rule, joint trustees must act unanimously in exercising trust powers, meaning all must concur in decisions unless the trust instrument or governing statute provides otherwise. This unanimity requirement distinguishes joint trustees from most other co-fiduciary arrangements and has significant practical consequences for trust administration.
Common Confusion
JOINT TRUSTEES vs. CO-TRUSTEES: These terms are often used interchangeably in practice, and in modern usage they are functionally synonymous. Some older authority distinguished between them on technical grounds, but contemporary trust law and the Uniform Trust Code treat the terms as equivalent. Researchers should not assume a meaningful legal distinction when the terms appear in different sources — the difference is more likely authorial habit than legal substance.
JOINT TRUSTEES vs. SUCCESSOR TRUSTEES: Joint trustees hold office simultaneously. A successor trustee holds office sequentially — stepping in only when a prior trustee vacates the position. The two arrangements create entirely different administrative structures and should not be confused when reading trust instruments or historical records.
Core Elements
Unanimity of Action: At common law, joint trustees must act unanimously. A decision made by fewer than all trustees, without proper authority, is generally voidable. This rule is strict enough that a dissenting trustee who nevertheless acquiesces may be held liable for the resulting breach.
Shared Fiduciary Duty: Each joint trustee owes independent fiduciary duties to the beneficiaries. A trustee cannot escape liability by deferring entirely to a co-trustee. Passive acquiescence in a co-trustee's misconduct can itself constitute a breach.
Indivisibility of the Trust Office: Joint trustees hold the trust office as a unit. The trust property is not divided among them — all joint trustees hold title collectively.
Survival of the Trust: At common law, the death or incapacity of one joint trustee did not extinguish the trust, but it could suspend administration until a successor was appointed. Modern statutes typically allow the remaining trustees to continue acting, subject to any requirements to notify a court or appoint a replacement.
Why It Matters in Research
The unanimity rule is the central research trap. Older cases and treatises treat this requirement with considerable strictness, and a researcher reading historical materials may encounter holdings that appear extreme by modern standards — e.g., a trust transaction voided because one of three trustees failed to sign. Modern trust codes, including the Uniform Trust Code, have softened this rule in some circumstances by allowing majority action when a trustee is unavailable or unreachable, but this modernization is not universal and is not retroactive on older instruments.
Liability exposure among joint trustees is an area of frequent research need. The rule that each trustee bears independent responsibility — and cannot shelter behind a co-trustee's authority — is well-established but applied unevenly in historical sources. Rapalje & Lawrence's abbreviated entry (directing readers elsewhere) reflects that the term was treated as largely definitional in the nineteenth century, with the substantive doctrine addressed under broader trust headings. Researchers working in older digests should search under TRUST and TRUSTEE rather than expecting the joint trustees entry itself to carry the analytical weight.
Institutional co-trustees present a modern complication absent from historical sources. Trust instruments increasingly pair an individual trustee (often a family member) with a corporate trust company. The governance rules for this arrangement — who can act on what, how disagreements are resolved — are largely a creature of the trust instrument and modern statute, and historical dictionary authority offers little guidance. Corpus materials on this topic will be found in modern practice guides and state trust codes rather than in the historical dictionaries.
The connection to trust decanting is worth flagging. When joint trustees exercise a power to decant — distributing trust assets into a new trust — questions arise about whether all trustees must concur and how dissent is handled. This is an active area of modern trust law entirely absent from historical sources.
Historical Dictionary Support
Black's Law Dictionary and Bouvier's Law Dictionary give identical one-sentence definitions: two or more persons entrusted with property for the benefit of others. The brevity is telling — both sources treated the term as essentially self-defining, with the substantive doctrine residing in surrounding entries on trusts and trustees generally. Neither source addresses the unanimity rule under this heading, the liability of joint trustees to one another or to beneficiaries, or any mechanism for resolving disagreement among co-trustees.
Rapalje & Lawrence's entry is abbreviated to a cross-reference, consistent with that dictionary's practice of consolidating related terms. The cross-reference direction ("See JOINT AD-") almost certainly points to JOINT ADMINISTRATORS or a related co-fiduciary entry, suggesting that Rapalje & Lawrence analyzed joint fiduciary arrangements as a unified doctrinal category rather than parsing trustees separately.
No historical source in the corpus addresses institutional joint trustees, majority-action statutes, or the interaction between joint trustee governance and modern decanting powers. For those subjects, the historical dictionaries are silent by necessity — the questions are modern.
Jurisdictional Note
The unanimity rule remains the default at common law and under many state trust statutes, but the Uniform Trust Code (adopted in whole or part in a majority of states) permits remaining trustees to act when a co-trustee is unavailable in certain circumstances. State variations on this point are substantial enough to require jurisdiction-specific research before advising on any joint trustee governance question.
Encyclopedia Cross-Reference
The Law Mind Trusts, Estates & Probate Encyclopedia — estates_83: Delegation of Trustee Duties — Prudent Delegation and Co-Trustees
The Law Mind Trusts, Estates & Probate Encyclopedia — estates_88: Decanting — Trustee Power to Distribute to a New Trust