Mo. Rev. Stat. § 340.318
If a certificate holder fails to submit an application and fees within thirty days of expiration of the certificate, the executive director shall notify the certificate holder that the application and fees have not been received and that the certificate holder's failure to respond within ten days will result in his or her certificate being declared noncurrent. The notification shall be sent by certified mail, return receipt requested, to the certificate holder's last known business and residence addresses. If the application and fee is not received within ten days after the return receipt is received, the certificate shall be declared noncurrent and the executive director shall notify the certificate holder of such declaration by certified mail, return receipt requested, at the certificate holder's last known business and residence addresses that his or her certification has been declared noncurrent and that the certificate holder shall not practice as a veterinary technician until he or she applies for reinstatement and pays the required fees.
§ 340.318, RSMo