(c) Extension of time for institutions of collection proceedings by agreement. — The Tax Commissioner and the taxpayer may enter into written agreement to extend the period within which the Tax Commissioner may institute proceedings for the collection of the amount found to be due under an assessment which has become final, or the amount determined to be due by methods provided by law other than the issuance of the assessment, of any tax, additions to tax, penalties or interest imposed by this article or any of the other articles of this code to which this article is applicable. This period may not exceed two years. The period so agreed upon may be extended for additional periods not in excess of two years each by subsequent agreements in writing made before the expiration of the period previously agreed upon.

An extension of a tax lien, including an extension agreed to in writing by the taxpayer and the Tax Commissioner, beyond 10 years is not effective under the provisions of this section unless the extension is docketed by the Tax Commissioner in the office of the county commission as is required under §38-10C-1 et seq. of this code for docketing tax liens.