Use Form 80-320 if your 2018 Mississippi income tax liability exceeds $200 to calculate interest on underpayment of estimated tax. This
form is also used to calculate late payment interest and penalty, and the late filing penalty for the Resident Individual Income Tax Return
(Form 80-105), the Non-Resident/Part-Year Resident Return (Form 80-205) and EZ Individual Income Tax Return (Form 80-110).
