Income Tax: Penalty and Interest
Delinquent Penalty and Interest:
If at least 90 percent of the tax liability is not paid by the original due date of the return, the unpaid tax becomes delinquent and a penalty of 5 percent shall be charged thereon.
If less than 100 percent of the tax liability is paid by the original due date of the return, interest on the unpaid amount is assessed, even when no delinquent penalty is assessed. The unpaid tax becomes delinquent and interest is charged at the rate of 1.25 percent per month from the date of the delinquency until paid.
Underpayment of Estimated Tax Penalty:
Estimated tax payments were required if the tax liability exceeds withholding (if applicable) by $500 or more. To avoid the Underpayment of Estimated Tax Interest, timely filed estimated tax payments and withholding (if applicable) are required to be equal to the smaller of 70% of the current year tax liability or 100% of the prior year tax liability.
The Underpayment of Estimated Tax Interest due on any quarterly due date is computed at a rate of 20% per annum for the period of underpayment.
Note: No Underpayment of Estimated Tax Interest will be imposed if the tax liability shown on the return is less than $1,000.