Conn. Gen. Stat. § 12-731
In the event that the amount of tax is understated on the taxpayer's return due to a mathematical error, the Commissioner of Revenue Services shall notify the taxpayer that an amount of tax in excess of that shown on the return, plus interest at the rate of one per cent per month or fraction thereof from the due date of such tax, is due and has been assessed. Such a notice of additional tax due shall not be considered a notice of a deficiency assessment nor shall the taxpayer have any right of protest or appeal as in the case of a deficiency assessment based on such notice, and the assessment and collection of the amount of tax erroneously omitted in the return shall not be prohibited by any provision of this chapter.
Conn. Gen. Stat. § 12-731
( June Sp. Sess. P.A. 91-3, S. 82, 168; May Sp. Sess. P.A. 92-5, S. 21, 37; P.A. 95-26, S. 42, 52.)