Missouri Laws 145.711 – Deficiency in tax paid — notice — assessment — time limitations
1. Except as otherwise provided in this section, a notice of deficiency shall be mailed to the taxpayer within three years after the return was filed. No deficiency shall be assessed or collected unless the notice is mailed within the three-year period or the period otherwise fixed.
2. If no return is filed or a false and fraudulent return is filed with intent to evade the tax imposed by sections 145.011 to 145.995, a notice of deficiency may be mailed to the taxpayer at any time.
3. If a taxpayer fails to comply with the requirements of section 145.601 by not reporting a change or correction or by not filing an amended return, a notice of deficiency may be mailed to the taxpayer within one year after the director of revenue shall become aware of the determination. A notice under this subsection shall be limited to the effects on the Missouri estate tax of the issues on which the federal determination is based.
4. If the taxpayer shall, pursuant to section 145.601, report a change or correction or file an amended return or report a change or correction which is treated in the same manner as if it were a deficiency for federal estate tax purposes, the assessment (if not deemed to have been made upon the filing of the report or amended return) may be made at any time within one year after the report or amended return was filed. A notice under this subsection shall be limited in the manner provided in subsection 3 of this section.
5. Where, before the expiration of the time prescribed in this section for the assessment of a deficiency, both the director of revenue and the taxpayer shall have consented in writing to its assessment after such time, the deficiency may be assessed at any time prior to the expiration of period agreed upon. The period so agreed may be extended by subsequent agreement in writing made before the expiration of the period previously agreed upon.
6. For purposes of this section a return filed before the last day prescribed by law or by regulation promulgated pursuant to law for the filing thereof shall be deemed to be filed on such last day.