Mo. Rev. Stat. § 140.440

Every holder of a certificate of purchase shall before being entitled to apply for deed to any tract or lot of land described therein pay all taxes that have accrued thereon since the issuance of said certificate, or any prior taxes that may remain due and unpaid on said property, and the lien for which was not foreclosed by sale under which such holder makes demand for deed, and any purchaser that shall suffer a subsequent tax to become delinquent, such first purchaser shall forfeit all liens on such lands so purchased. Said holder of a certificate of purchase permitting a subsequent certificate to issue on the same property shall, on notice from the county collector, surrender said certificate of purchase immediately to the county collector. Upon surrender of such certificate of purchase any surplus moneys paid by the first holder of the certificate of purchase and remaining unclaimed pursuant to section 140.230 shall be paid without interest to such holder of the certificate.