(1) As soon as practical after a return is filed, the department will examine the return and verify the amount of tax. If the department determines that the tax liability is greater than the amount previously paid, it will mail notice of the additional tax plus penalty and interest as outlined in 15-1-216, MCA.

(2) Within 30 days of the date of the deficiency notice, the taxpayer may file a written request for informal review or a written objection as provided in ARM 42.2.510.