MO Rev Stat § 506.150 (2021)
2021 Missouri Revised Statutes|Title XXXV - Civil Procedure and Limitations|Chapter 506 - Commencement of Actions and General Provisions|Section 506.150 - Summons and petition, how served — service by mail, authorized when — notice by mail and acknowledgment form.

Effective - 28 Aug 1988   506.150. Summons and petition, how served — service by mail, authorized when — notice by mail and acknowledgment form. — 1. The summons and petition shall be served together. Service shall be made as follows:  (1) Upon an individual, including an infant or disabled or incapacitated person not having a legally appointed guardian or conservator, by delivering a copy of the summons and of the petition to him personally or by leaving a copy of the summons and of the petition at his dwelling house or usual place of abode with some person of his family over the age of fifteen years, or by delivering a copy of the summons and of the petition to an agent authorized by appointment or required by law to receive service of process;  (2) If the infant or disabled or incapacitated person has a legally appointed conservator, by serving a copy of the summons and of the petition on such conservator as provided in subdivision (1) of this subsection;  (3) Upon a domestic or foreign corporation or upon a partnership, or other unincorporated association, when by law it may be sued as such, by delivering a copy of the summons and of the petition to an officer, partner, a managing or general agent, or by leaving the copies at any business office of the defendant with the person having charge thereof, or to any other agent authorized by appointment or required by law to receive service of process and, if the agent is one authorized by statute to receive service and the statute so requires, by also mailing a copy to the defendant;  (4) Upon a domestic corporation that has been dissolved according to law, by delivering a copy of the summons and of the petition to the last registered agent of the corporation or upon the secretary of state, and if upon the secretary of state, the secretary of state shall send a copy of the summons and petition by registered mail, requesting a return receipt signed by addressee only, addressed to each member of the last board of directors of the corporation at the address of such directors, as shown by the secretary of state's records;  (5) Upon a public, municipal, governmental, or quasi-public corporation or body, by delivering a copy of the summons and of the petition to the clerk of the county commission in the case of a county, to the mayor or city clerk or city attorney in the case of a city, and to the chief executive officer in the case of any other public, municipal, governmental or quasi-public corporation or body. If there is, for the time being, no such officer as is specified by this subdivision, the court may designate an appropriate officer to whom the copies of the summons and petition may be delivered in order to effect service.  2. When a defendant shall acknowledge in writing, endorsed on the writ, signed by his own proper signature, the service of such writ, and waive the necessity of the service thereof by an officer, such acknowledgment shall be deemed as valid as service in the manner provided by law.  3. In all cases when the defendant shall refuse to hear the writ read or to receive a copy of the writ or petition, the offer of the officer to read the same or to deliver a copy thereof, and such refusal, shall be sufficient service of such writ.  4. Service of the summons and petition upon a defendant of any class referred to in subdivision (1) or (3) of subsection 1 of this section may be made by the plaintiff or by any person authorized to serve process pursuant to section 506.140, by mailing a copy of the summons and petition by first-class mail, postage prepaid, to the person to be served, together with two copies of a notice and acknowledgment conforming substantially to the form contained in subsection 5 of this section and a return envelope, postage prepaid, addressed to the sender. If no acknowledgment of service under this subsection is received by the sender within thirty days after the date of mailing, service of the summons and petition shall be made as otherwise provided by this section or supreme court rule. Unless good cause is shown for not doing so, the court shall order the payment of the costs of personal service by the person served if such person does not complete and return within thirty days after mailing the notice and acknowledgment of receipt of summons.  5. The acknowledgment form required by subsection 4 of this section shall be substantially as follows:    Notice and Acknowledgment for Service by Mail   Circuit Court for ______ County   Division ______   Civil Action, File Number   A.B., )   Plaintiff, )    vs. )   C.D., )   Defendant. )   NOTICE AND ACKNOWLEDGMENT   OF RECEIPT OF SUMMONS   AND PETITION NOTICE   TO: (Insert the name and address of the person to be served.)   The enclosed summons and petition are served pursuant to section 506.150, RSMo.   You must complete the acknowledgment part of this form and return one copy of the completed form to the sender within thirty days.   You must sign and date the acknowledgment. If you are served on behalf of a corporation, unincorporated association, including a partnership, or other entity, you must indicate under your signature your relationship to that entity. If you are served on behalf of another person and you are authorized to receive process, you must indicate under your signature your authority.   If you do not complete and return the form to the sender within thirty days, you or the party on whose behalf you are being served may be required to pay any expenses incurred in serving a summons and petition in any other manner permitted by law.   If you do complete and return this form, you or the party on whose behalf you are being served must answer the petition within thirty days. If you fail to do so, judgment by default will be taken against you for the relief demanded in the petition.   I declare, under penalty of filing a false affidavit, that this Notice and Acknowledgment of Receipt of Summons and Petition was mailed on (insert date).   ___________________________________________________    Signature     ___________________________________________________    Relationship to Entity/Authority to Receive Service of Process    __________________        (Date of Signature)     ­­-------- (L. 1943 p. 353 § 27, A.L. 1974 H.B. 1639, A.L. 1983 S.B. 44 & 45, A.L. 1985 S.B. 5, et al., A.L. 1988 S.B. 425)  (1975) Facts held to show adequate service on foreign corporation actually doing business in the state. Ward v. Cook United Inc. (A.), 521 S.W.2d 474. (1986) The substitute service provided by subdivision (1) of subsection 1 of this section is not a substitute for service upon persons listed in subdivision (3) of subsection 1 of this section, providing method of service on corporations. Kirlin v. Dalco, 719 S.W.2d 516 (Mo.App.).