Mo. Rev. Stat. § 143.331 : TAXATION AND REVENUE — Income Tax —ESTATES, TRUSTS, AND BENEFICIARIES, RESIDENT — Resident estate or trust defined TEXT PDF A "resident estate or trust" means: (1) The estate of a decedent who at his or her death was domiciled in this state; (2) A trust that: (a) Was created by will of a decedent who at his or her death was domiciled in this state; and (b) Has at least one income beneficiary who, on the last day of the taxable year, was a resident of this state; or (3) A trust that: (a) Was created by, or consisting of property of, a person domiciled in this state on the date the trust or portion of the trust became irrevocable; and (b) Has at least one income beneficiary who, on the last day of the taxable year, was a resident of this state. § 143.331, RSMo L. 1972 S.B. 549, A.L. 2000 S.B. 896