The interest rate applied to individual taxpayers, estates, trusts, and pass-through entities changed for the calendar year beginning January 1, 2018. The interest rate for all other taxpayers remains the same.
The rate in effect in 2018 for individuals, estates, trusts, and pass-through entities is 4%. This rate applies to:
- Unpaid taxes when due, including delinquent taxes and deficiency assessments.
- Interest on the underpayment of estimated taxes due for the 2017 tax year.
- Interest on refunds when applicable.
This interest rate is determined annually, and is based on the interest rate established by the Internal Revenue Service for the third quarter of the preceding year.
The rate in effect in 2018 for all other taxpayers is 12%.