K-210: Individual Underpayment of Estimated Tax Schedule (2025)
Kansas · Kansas DOR · Used for tax years 2025
Kansas Schedule K-210 determines whether your 2025 individual income tax was fully paid throughout the year through withholding and estimated tax payments. It checks exceptions to the underpayment penalty and calculates any penalty to report on Form K-40.
Who files this form
Individual taxpayers, including farmers and fishers, use Schedule K-210 to check whether their income tax was fully paid throughout the year through withholding and estimated payments.
You must complete this form if your 2025 tax due on Form K-40, line 18, minus withholding and tax credits, is $500 or more. Do not subtract estimated tax payments when checking this threshold. You may owe an underpayment penalty.
Farmers and fishers may be exempt if at least two-thirds of their annual gross income is from farming or fishing and they filed Form K-40 and paid the tax on or before March 1, 2026. If exempt, write “Exempt–farmer/fisher” on line 1 and leave the rest of the schedule blank. If you meet the income test but did not file and pay by that date, use K-210 to determine whether you owe a penalty.
When it's due
For tax year 2025, K-210 lists these estimated tax installment due dates for calendar-year taxpayers:
- April 15, 2025
- June 15, 2025
- September 15, 2025
- January 15, 2026
If a due date falls on a Saturday, Sunday, or legal holiday, use the next regular workday.
Other dates affecting the 2025 penalty:
- January 31, 2026: Taxpayers other than farmers and fishers do not have to make the January 15 quarterly payment if they filed Form K-40 and paid the tax in full on or before this date.
- March 1, 2026: Qualifying farmers and fishers may be exempt from the penalty if they filed Form K-40 and paid the tax on or before this date.
- April 15, 2026: The penalty calculation ends on this date or the date the tax was paid, whichever is earlier.
What you'll need
Have these forms and details ready:
- Your name as shown on Form K-40 and your Social Security number.
- Your 2025 Form K-40, including line 18, total Kansas income tax withheld, and the credit for taxes paid on K-120S from line 25.
- Your 2024 Form K-40, if filed, for the prior-year tax liability on line 19.
- The amounts and dates of your 2025 estimated tax payments.
If you use the annualized-income exception, you also need income for the periods listed in the schedule, your standard or itemized deductions, and your exemption allowance. Enclose a schedule showing how you calculated annualized income and tax.
Common mistakes
- Using a weekend or holiday due date without adjustment. The schedule says to use the next regular workday.
- Entering a prior-year amount when line 3 should be zero. Enter zero if you did not file a prior-year income tax return or if your prior-year Form K-40, line 19, was zero.
- Using the precomputed days after a late payment. The instructions say to disregard the precomputed days on lines 13 and 14 if payments were late and calculate the days to the payment date.
- Leaving out the annualized-income calculation. If you use that exception, enclose your computation of annualized income and tax.
- Forgetting to carry the penalty to Form K-40. Enter the total from K-210, line 18, on Form K-40, line 31, Estimated Tax Penalty.
Questions people ask
Does completing K-210 mean I owe a penalty?
No. You are not subject to a penalty for a payment period if your payments on line 8 equal or exceed the applicable exception amount on line 9, 10a, or 10b for that period.
What does the first penalty exception compare?
Line 9 uses the smaller of line 2 or line 3, multiplied by the percentage shown for each payment period. Line 2 is 90% of your 2025 Form K-40, line 18, or 66 2/3% for farmers and fishers. Line 3 is your prior-year tax liability. If line 8 equals or exceeds line 9 in every column, no penalty is due and no further entries are required.
Can I use annualized income to check for an exception?
Yes. Exception 2 uses tax on annualized 2025 income. Enclose your calculation of annualized income and tax. Farmers and fishers complete only the last column of line 10b.
What rates are used to calculate the penalty?
The schedule uses 9% through December 31, 2025, and 8% from January 1, 2026, through the date the tax was paid or April 15, 2026, whichever is earlier.