Mo. Rev. Stat. § 393.939
Nothing in sections 393.900 to 393.951 shall be construed to prohibit the payment by a company of all or any part of its indebtedness prior to the date when such indebtedness shall become due.
(L. 1999 H.B. 450 § 14 merged with S.B. 160 & 82 § 14)