Missouri Revised Statutes Title XXVII. Debtor-Creditor Relations § 428.110. Filing officer may reject lien, exceptions--filing officer to accept notice of invalid lien, when

1. Any filing officer may reject for filing or recording any nonconsensual common law lien. This section shall not be construed to permit rejection of a document that is shown to be authorized by contract, lease or statute or imposed by a state or federal court of competent jurisdiction or filed by a licensed attorney, a financial institution including, but not limited to, any commercial bank, savings and loan association or credit union or a Missouri state licensed mortgage company or mortgage broker.

2. If a nonconsensual common law lien has been accepted for filing, the filing officer shall accept for filing a sworn notice of invalid lien on a form provided by the filing officer signed and submitted by the person against whom such lien was filed or such person's attorney. The form shall be captioned “Notice of Invalid Lien” and shall state the name and address of the person on whose behalf such notice is filed, the name and address of the lien claimant and a clear reference to the document or documents the person believes constitute a nonconsensual common law lien. A copy of the notice of invalid lien shall be mailed by the filing officer to the lien claimant at the lien claimant's last known address within one business day. No filing officer, county or the state shall be liable for the acceptance for filing of a nonconsensual common law lien, nor for the acceptance for filing of a sworn notice of invalid lien pursuant to this subsection.