Mo. Rev. Stat. § 400.9-110: Security interests arising under Article 2 or 2A.

A security interest arising under sections 400.2-401, 400.2-505, 400.2-711(3) or 400.2A-508(5) is subject to this article. However, until the debtor obtains possession of the goods:

(1) The security interest is enforceable, even if section 400.9-203(b)(3) has not been satisfied;

(2) Filing is not required to perfect the security interest;

(3) The rights of the secured party after default by the debtor are governed by article 2 or 2A; and

(4) The security interest has priority over a conflicting security interest created by the debtor.