K-40: Individual Income Tax Return (original and amended) (2025)
Kansas · Kansas DOR · Used for tax years 2025
Form K-40 is the 2025 Kansas Individual Income Tax Return, used for original and amended returns. It reports income, deductions, exemptions, tax, credits, withholding and payments to calculate the amount you owe or your refund.
What you'll need
Have your federal income tax return available for your federal adjusted gross income, and W-2s or 1099s for Kansas income tax withheld.
Depending on the entries you make, the form calls for:
- Schedule S for modifications. Part-year residents and nonresidents must complete Schedule S, Part B.
- Kansas Schedule A if you itemize deductions.
- Other states’ tax returns enclosed when claiming the credit for taxes paid to other states.
- Appropriate credit schedules enclosed for other credits.
- K-9 enclosed when claiming credit for tax paid on the K-120S.
For dependents, provide each person’s name, date of birth, relationship and Social Security number. Enclose a separate schedule if necessary.
How to file
Complete the 2025 K-40 with your identifying information, filing status, residency status and tax amounts. If this is an amended return, mark one of the three amended-return boxes.
Sign and date the return. Your spouse must also sign and date it if you are married filing jointly. Enclose any necessary documents. Do not staple.
Mail to:
Kansas Income Tax
Kansas Dept. of Revenue
PO Box 750260
Topeka, KS 66699-0260
Common mistakes
- Enter amounts in whole dollars only, and shade the box for negative amounts.
- Use all capital letters when entering the first four letters of your last name and your spouse’s last name.
- Mark only one filing status and one residency status. Do not select head of household when filing a joint return.
- Make sure the exemption selection matches your filing status.
- Do not include yourself or your spouse in the dependent count or dependent information list.
- Enter the Total Kansas Exemption Amount on page 2, line 5 as well as on the front of the form.
- Remember that donations on lines 35 through 42 reduce your refund or increase the amount you owe.
- Enclose necessary documents, but do not staple them.
Questions people ask
Can I use this form to amend my 2025 Kansas return?
Yes. Mark one amended-return box: “Amended affects Kansas only,” “Amended Federal tax return,” or “Adjustment by the IRS.”
What extra schedule do part-year residents and nonresidents complete?
The form directs both groups to complete Schedule S, Part B.
Is there an additional exemption for a dependent child born in 2025?
Yes. Enter the number of children you may claim as dependents who were born during the tax year, multiply by $2,320 and enter the total in the additional-exemption box.
Can I apply an overpayment to next year’s estimated tax?
Yes. On line 34, enter the amount you want applied to your 2026 estimated tax.
Can I authorize the department to discuss my return with my preparer?
Yes. The form provides an authorization for the Director of Taxation or the Director’s designee to discuss your return and enclosures with your preparer.