1. As soon as is practicable after the return is filed, the director shall examine it to determine the correct amount of tax. If the director finds that the amount of tax shown on the return is less than the correct amount, he shall notify the taxpayer of the amount of the deficiency proposed to be assessed. If the director finds that the tax paid is more than the correct amount, he shall credit the overpayment against any taxes due under sections 148.010 to 148.110 from the taxpayer and refund the differences. No deficiency shall be proposed and no refund shall be made pursuant to this or any section of sections 148.010 to 148.110 unless the amount exceeds one dollar.

2. If the taxpayer fails to file a return, the director shall estimate the par value of the taxpayer’s shares and surplus employed in this state and the taxpayer’s net income and the tax thereon from any available information and notify the taxpayer of the amount proposed to be assessed as in the case of a deficiency.

3. The notice required by subsections 1 and 2 of this section, hereafter referred to as a notice of deficiency, shall set forth the reason for the proposed assessment. The notice of deficiency shall be mailed by certified or registered mail to the taxpayer at its last known address. If the taxpayer’s existence has terminated, a notice of deficiency may be mailed to its last known address unless the director has received notice of the existence and address of a person to receive notices with respect to such taxpayer.