Mo. Rev. Stat. § 145.301
If an executor or other fiduciary receives a discharge pursuant to Internal Revenue Code Section 2204 (a) or (b) and if the fiduciary makes written application to the director of revenue for determination of the amount of the tax and discharge from personal liability, the director within two months after receiving satisfactory evidence of the Section 2204 discharge, but not after the expiration of the period prescribed for the assessment of the tax in section 145.711, shall notify the fiduciary of the amount of the tax. The fiduciary, on payment of the amount of which he is notified (other than any amount the time payment of which is extended under section 145.551), and on furnishing any bond which may be required for any amount for which the time for payment is extended, shall be discharged from personal liability for any deficiency in tax thereafter found to be due and shall be entitled to a receipt or writing showing the discharge.
§ 145.301, RSMo
Effective 1/1/1981