Mo. Rev. Stat. § 452.760: Notice — opportunity to be heard — joinder.

1. Before a child custody determination is made under sections 452.700 to 452.930, notice and an opportunity to be heard in accordance with the standards of section 452.762 shall be given to:

(1) All persons entitled to notice under the provisions of the law of this state as in child custody proceedings between residents of this state;

(2) Any parent whose parental rights have not been previously terminated; and

(3) Any person having physical custody of the child.

2. Sections 452.700 to 452.930 shall not govern the enforceability of a child custody determination made without notice and an opportunity to be heard.

3. The obligation to join a party and the right to intervene as a party in a child custody proceeding under sections 452.700 to 452.930 are governed by the law of this state as in child custody proceedings between residents of this state.