If a Notice of Deficiency (“NOD”) has been issued and a Protest has been filed by the taxpayer, then the amount, of the tax deficiency, shall be deemed assessed, upon the date, when the decision, of the Illinois Department of Revenue, becomes final.
Sixty (60) days after the date of the NOD, if the taxpayer has not filed a Protest, then the NOD shall constitute an assessment, of the tax deficiency, so delineated.