Estimated Income Tax Payments and Penalty for Underpayment of Estimated Income Tax. You may owe a penalty if your estimated income tax payments did not total at least:
-90% of the tax shown on your 2018 Nebraska return; or
-100% of the tax shown on your 2017 return; or
-110% of the tax shown on your 2017 return if AGI on the return was more than $150,000; or, if your filing status is married, filing separately, more than $75,000.
See the Individual Underpayment of Estimated Tax, Form 2210N, instructions.
An individual who did not pay enough estimated income tax by any of the applicable due dates (April 15, June 15, September 15, and January 15), or who did not have enough state income tax withheld, will be assessed a penalty. This may be true even if you are due a refund. The underpayment penalty is calculated separately for each installment due date (four equal and timely payments). You may owe a penalty for an earlier payment that was due, even if you paid enough estimated income tax later to make up the underpayment.