Modifies provisions relating to civil jurisprudence

HB 1259 updates Missouri's income tax code to clarify how taxpayers can claim credits for income taxes paid to other states. It limits these credits to the portion of Missouri tax attributable to out-of-state income and adds specific rules for S corporations and bank shareholders regarding tax credits. The bill also modifies estate and trust tax calculations and allows trustees to change a trust's principal administration location without court approval, provided beneficiaries are notified 60 days in advance. These changes primarily affect Missouri taxpayers with income from other states, S corporation shareholders, and trust administrators. The bill does not create new taxes but adjusts existing credit mechanisms and trust administration procedures.