Mo. Rev. Stat. § 67.451
Any city in which voters have approved fees to recover costs associated with enforcement of municipal housing, property maintenance, or property nuisance ordinances may include any unrecovered costs or fines relating to the real property in the annual real estate tax bill for the property where such ordinance violations existed. Notwithstanding the last sentence of subsection 5 of section 479.011, the officer in charge of finance shall cause the amount of unrecovered costs or unpaid fines which are delinquent for more than a year to be added to the annual real estate tax bill for the property if such property is still owned by the person incurring the costs or fines and the costs and fines shall be collected by the city collector or other official collecting taxes in the same manner and procedure for collecting real estate taxes. If the costs and fines are not paid by December thirty-one of the year in which the costs and fines are included in the tax bill, the tax bill shall be considered delinquent, and the collection of the delinquent bill shall be governed by laws governing delinquent and back taxes. The tax bill shall be deemed a personal debt against the owner from the date of issuance, and shall also be a lien on the property from the date the tax bill becomes delinquent until paid. Notwithstanding any provision of the city's charter to the contrary, the city may provide, by ordinance, that the city may discharge all or any portion of the unrecovered costs or fines added pursuant to this section to the tax bill upon a determination by the city that a public benefit will be gained by such discharge, and such discharge shall include any costs of tax collection, accrued interest, or attorney fees related to the tax bill.
§ 67.451, RSMo