When the Agency of Transportation discovers from the examination of the return or otherwise that the revenue of any company has not been assessed, it may at any time within four years after the time when the return was due assess the revenue and give notice to the company of the assessment and, within 30 days, the company shall have an opportunity to confer with the Agency as to the proposed assessment. The limitation of four years to the assessment of a tax or additional tax shall not apply to the assessment of additional taxes upon fraudulent returns. After the expiration of 30 days from notification, the Agency shall reassess the revenue of the company which it finds has not been assessed and shall give notice to the company of the amount of the tax and interest and penalties, if any, and that amount shall be due and payable within ten days from the date of the notice. No additional tax amounting to less than $1.00 shall be assessed. (Added 1985, No. 222 (Adj. Sess.), § 1.)