Mo. Rev. Stat. § 140.120
If it appears to any county commission, that any tract of land or town lot contained in the back tax book is not worth the amount of taxes, interest and cost due thereon, as charged in the back tax book or that the same would not sell for the amount of the taxes, interest and cost, the commission may compromise the taxes with the owner of the tract or lot. Upon payment to the collector of the amount agreed upon, a certificate of redemption shall be issued under the seal of the commission, which shall release the lands from the lien of the state and all taxes due thereon, as charged on the back tax book. If the commission compromises and accepts a less amount than appears to be due on any tract of land or town lot, as charged on said back tax book, the commission shall order the amount so paid to be distributed to the various funds to which the taxes are due, in proportion as the amount received bears to the whole amount charged against the tract or lot.
§ 140.120, RSMo