Louisiana Form R-210R, Underpayment of Individual Income Tax Penalty Computation, is used by resident filers to determine whether they owe a penalty for not paying enough Louisiana income tax during the year. This may happen if a taxpayer did not make enough estimated tax payments, did not make payments on time, or had too little Louisiana tax withheld.
Note: Form R-210R is generally completed when a taxpayer must calculate an underpayment penalty or determine whether an exception applies. When completed in the program, Form R-210R is included with the Louisiana return.
What is the Louisiana underpayment penalty?
According to the Louisiana Department of Revenue, Louisiana law provides for a 12% annual penalty for underpayment of individual income tax. The penalty may apply if you did not pay enough estimated tax during the year or did not make estimated tax payments by the required due dates. The penalty is imposed on each underpayment for the number of days it remains unpaid.
Who may need Form R-210R?
You may need Form R-210R if you were required to make Louisiana estimated tax payments for 2025 and did not pay enough tax during the year through withholding, estimated payments, credits, or an extension payment.
Louisiana generally requires estimated tax payments if your expected Louisiana income tax after credits and withholding is more than:
- $1,000 for single filers
- $2,000 for married filing jointly filers
You may also need this form if your income changed during the year and you became required to make estimated payments after the year had already started. In that case, Louisiana may require fewer installments depending on when the requirement was first met.
Estimated Payment Due Dates
For calendar-year taxpayers, Louisiana generally requires estimated tax payments by the following dates:
| Installment | Due date |
| 1st installment | April 15 |
| 2nd installment | June 15 |
| 3rd installment | September 15 |
| 4th installment | January 15 of the following year |
If you were not required to make estimated payments until later in the year because of a change in income, the number of required installments may be reduced.
How does Form R-210R calculate the penalty?
Form R-210R first calculates the required annual payment. For 2025, the required annual payment is generally based on the smaller of:
- Your 2025 Louisiana income tax liability, or
- Your 2024 Louisiana income tax liability.
If you did not file a 2024 Louisiana return or were a part-year resident in 2024, special rules apply.
The form then divides the required annual payment by the number of required installments and compares each required installment to the payments available for that period. Payments may include:
- Estimated tax payments
- Louisiana withholding
- Credit carryforwards
- Certain extension payments
If a period is underpaid and no exception applies, Louisiana calculates the penalty using a 12% annual rate based on the number of days the underpayment remained unpaid.
Are there exceptions to the penalty?
Yes. Form R-210R includes several exceptions that may reduce or eliminate the underpayment penalty.
- Exception 1- No Estimated Tax Requirement: You are not responsible for a Louisiana underpayment penalty if you were not required to make estimated tax payments because you did not reasonably expect your Louisiana tax liability to exceed $1,000 ($2,000 if filing Married Filing Jointly). If this exception applies, you generally do not need to continue completing the form.
- Exception 2- Prior year tax liability: You may qualify for this exception if your payments for each installment period equal or exceed the amount required under Louisiana's prior-year safe harbor calculation. This exception does not apply if you were a part-year resident in 2024.
- Exception 3- Prior year income using current year rules: You may qualify if your payments for each installment period equal or exceed the amount determined using your prior-year income and current-year tax rules. This exception does not apply if you were a part-year resident in 2024.
- Exception 4- Annualized income: This exception may benefit taxpayers whose income was not earned evenly throughout the year. It uses actual income received during specific periods to determine whether the required payments were made.
- Exception 5- Installment period income: This exception uses actual taxable income earned before each installment due date. If payments and withholding for a period are sufficient, the penalty may be reduced or eliminated for that installment period.
Special rules for farmers and fishermen
Program Entry
To calculate your Louisiana underpayment penalty, follow the steps below.
- State
- Edit Louisiana using the three dots
- Miscellaneous Forms
- Underpayment of Income Tax, Form R-210R