For individual income tax purposes only, failure to file penalties of five percent (5%) per month and failure to pay penalties of one percent (1%) per month are assessed simultaneously, not to exceed thirty-five percent (35%).

The underestimated tax penalty shall not be imposed if the tax liability for the current tax year is one thousand dollars ($250.00) or less.

The underestimated tax penalty shall not be imposed if the current year payments made equal or exceed ninety percent (90%) of the current year tax liability or one hundred percent (100%) of the preceding tax year liability and the preceding tax year was twelve (12) months.

The underestimated tax penalty is calculated by multiplying the underpayment for each quarter by .00027397, then multiplying this product by the number of days from the date the estimate payment was due to:

For purposes of this regulation, payments include taxes withheld from the taxpayer's wages and estimated tax payments. Estimated tax payments must be made by the required due dates. Payments made with an extension of time to file individual income tax returns do not constitute estimated tax payments.