K-40C: Composite Income Tax Schedule (Revision 2025-06)
Kansas · Kansas DOR · Used for tax years 2024, 2025, 2026
Schedule K-40C is the Kansas Composite Income Tax Schedule for S corporations and partnerships filing a composite return for nonresident owners. It reports each included owner's income, deductions, Kansas tax, estimated tax payments, and balance due or refund, and is enclosed wit
Who files this form
A partnership or S corporation required to file a Kansas income tax return may choose to file a composite return for its nonresident partners or shareholders who receive income from the entity. Filing a composite return is optional.
- An owner cannot be included if they have Kansas-source income other than income from that partnership or S corporation.
- Nonresident owners included in the composite return must not file a separate income tax return.
- A trust cannot use Schedule K-40C. It must file Kansas Form K-41 instead.
- K-40C cannot be used for a tax year in which the partnership or S corporation claims a special tax credit or a net operating loss.
When it's due
For the partnership’s or S corporation’s taxable year, the entity must file the composite return and pay any applicable tax on or before the 15th day of the fourth month following the close of that taxable year.
What you'll need
Have these forms and details available:
- Form K-40, which must be completed in the partnership’s or S corporation’s name and employer identification number (EIN).
- Form K-120S, for apportionable business income, total Kansas income, and each owner’s percentage from Part II, Column 4.
- Each included owner’s name, Social Security number, and state of residence.
- Federal return information for each owner’s filing status and dependents.
- Information needed for any applicable exemptions or additional standard deduction, including age, blindness, and qualifying disabled veteran status.
- The amount of Kansas estimated tax paid.
- The entity’s taxable-year dates and the tax preparer’s name and phone number.
Enclose a copy of Schedule K-40C with Form K-40.
How to file
- Complete Schedule K-40C with the information and calculations for each eligible nonresident owner.
- Complete a Kansas Individual Income Tax Return, Form K-40, in the partnership’s or S corporation’s name and EIN.
- Transfer the totals for Kansas nonresident tax, Kansas estimated tax, and balance due or refund to the applicable lines of Form K-40.
- Enclose a copy of K-40C with Form K-40. The partnership or S corporation files the composite return and pays any applicable tax.
The supplied text does not give a filing address or e-file instructions. The address listed on the schedule is for taxpayer assistance.
Common mistakes
- Using K-40C when it is not allowed. Trusts cannot file it, and entities cannot use it for a year when claiming a special tax credit or net operating loss.
- Including an ineligible owner. An owner with Kansas-source income outside the partnership or S corporation cannot be included.
- Claiming yourself or your spouse in the Total Kansas Exemptions box. The instructions specifically prohibit this.
- Using itemized deductions. Owners on a composite return must use the standard deduction.
- Leaving dollar amounts unrounded. Round all dollar figures to the nearest whole dollar.
- Relying on unchanged K-120S line numbers. The instructions warn that line references are subject to change.
Questions people ask
Does Kansas require written approval before filing a composite return?
The instructions state that the Kansas Department of Revenue does not currently require written approval.
Do included owners also file separate income tax returns?
No. The instructions say nonresident partners and shareholders included in a composite return must not file a separate income tax return.
Must an owner use the same filing status as on their federal return?
Generally, yes. However, an owner who used “Qualifying Widow(er) with Dependent Child” on the federal return must use “Head of Household” on K-40C.
Can owners claim an additional standard deduction?
An additional deduction is allowed for people who are age 65 or older and/or blind. All owners included in a composite return must use the standard deduction.
Where can I get help or obtain forms?
Contact the Kansas Department of Revenue’s Taxpayer Assistance Center at 785-368-8222. The schedule and other tax forms are available at ksrevenue.gov.