Missouri Revised Statutes Title XXXI. Trusts and Estates of Decedents and Persons Under Disability § 461.012. Nonprobate transfers subject to agreement of transferring entity, when

1. When any of the following is required, provision for a nonprobate transfer is a matter of agreement between the owner and the transferring entity, under such rules, terms and conditions as the owner and transferring entity may agree:

2. Whenever subsection 1 of this section is applicable, sections 461.003 to 461.081 do not impose an obligation on a transferring entity to accept an owner's request to make provision for a nonprobate transfer of property.

3. When a beneficiary designation, revocation or change is subject to acceptance by a transferring entity, the transferring entity's acceptance of the beneficiary designation, revocation or change relates back to and is effective as of the time when the request was received by the transferring entity.