In most instances, trust beneficiaries must be parties to a lawsuit when the lawsuit relates to the conduct of a trustee and/or the trust’s assets.
“A necessary [party] is one who is so vitally interested in the subject matter of controversy that a valid judgment cannot be effectively rendered without the party’s presence.” Jones v. Jones, 285 S.W.3d 356, 360 (Mo. Ct. App. 2009). Trust beneficiaries are necessary parties to actions involving or affecting a trust’s corpus. Pauli v. Spicer, 445 S.W.3d 667, 675 (Mo. Ct. App. 2014) (there is a “general rule that in suits involving trust property, both the trustee and beneficiaries are necessary parties”). Where a petition presents the issue of the conduct of the trustees and their handling of the trust, each beneficiary has an interest in that determination. Roth v. Lehman, 741 S.W.2d 860, 862 (Mo. Ct. App. 1987). The trust code defines a “beneficiary” to include, among others, any person who “[h]as a present or future beneficial interest in a trust, vested or contingent.” § 456.1-103(3), RSMo.
If a plaintiff fails to join a beneficiary/necessary party, the usual remedy is that a court orders the necessary party(ies) joined. In certain circumstances, the matter can be dismissed for failure to properly join.