Kansas tax deadlines in 2026: filing dates and estimated payments
Deadlines that fall in calendar 2026: the 2025 return and the 2026 estimated payments. Different year? See Kansas 2025 →
Kansas deadlines in 2026
| 2025 individual return due | April 15, 2026 |
|---|---|
| Extended filing deadline | October 15, 2026 |
| Payment due | April 15, 2026, extension or not |
| Final 2025 estimated payment | January 15, 2026 |
| 2026 estimated payments | April 15, 2026 · June 15, 2026 · September 15, 2026 · January 15, 2027 |
Conforms to the federal deadline.
Kansas estimated tax payments in 2026
Your estimated Kansas income tax after withholding and credits is $500 or more and withholding plus credits may be less than the smaller of 90% of 2026 tax or 100% of 2025 tax (nonresidents consider only Kansas-source income).
| Q1 (2026 tax year) | April 15, 2026 |
|---|---|
| Q2 (2026 tax year) | June 15, 2026 |
| Q3 (2026 tax year) | September 15, 2026 |
| Q4 (2026 tax year) | January 15, 2027 |
| Voucher | Form K-40ES |
| Underpayment safe harbor | No penalty if each payment is timely and total payments and credits are at least 90% (66 2/3% for farmers and fishers) of 2026 tax, or at least 100% of 2025 tax (12-month return with a liability), or at least 90% of tax on annualized income (Schedule K-210). |
| Pay online | kansas.gov |
Four vouchers; when the due date falls on a Saturday, Sunday or legal holiday substitute the next regular workday. The January 15, 2027 installment is not required if the 2026 return is filed and paid in full by January 31, 2027. Farmers/fishers: single payment due January 15, 2027, or file and pay by March 1, 2027. Kansas has no 110% high-income tier. Online payment also available by logging in to the Kansas Customer Service Center from ksrevenue.gov.
Source: ksrevenue.gov, read September 3, 2026. “Payments are due on or before the due dates on each voucher (April 15, 2026, June 15, 2026, September 15, 2026 and January 15, 2027”
All 51 jurisdictions in one table: state estimated tax payment dates for 2026.
Kansas extensions
Every state's rule in one table: which states accept the federal extension in 2026.
| Does Kansas accept the federal extension? | Yes. A federal extension is honored; no state form. |
|---|---|
| Original due date | April 15, 2026 |
| Extended due date | October 15, 2026 |
| Payment | Still due April 15, 2026. The extension is to file, not to pay. Not an extension to pay; 90% of the tax must be paid by April 15, 2026 to avoid a penalty and any remaining balance accrues interest. |
| How to get it | File federal Form 4868 and enclose a copy with Form K-40 when filed; make any extension payment with Form K-40V (check the extension box) by April 15, 2026. |
Kansas has no separate extension request form.
Source: ksrevenue.gov, read September 3, 2026. “If you file Form 4868 with the Internal Revenue Service requesting an automatic extension of time to file your federal tax return, you will automatically receive an extension of time to file your Kansas return.”
Federal deadlines in 2026
| 2025 Form 1040 | April 15, 2026 · extension October 15, 2026 |
|---|---|
| 2025 S-corp (1120-S) & partnership (1065) | March 16, 2026 |
| 2025 C-corp (Form 1120) | April 15, 2026 |
| 2026 federal estimated payments (1040-ES) | April 15, 2026 · June 15, 2026 · September 15, 2026 · January 15, 2027 |
Source: IRS Publication 509 and Form 1040-ES instructions, irs.gov.
Frequently asked questions
When are Kansas state taxes due in 2026?
Your 2025 Kansas individual income tax return is due April 15, 2026. If that date falls on a weekend or legal holiday, the deadline moves to the next business day. An extension moves the filing deadline to October 15, 2026, but any tax owed is still due on the original date.
When are Kansas estimated tax payments due in 2026?
Kansas estimated payments for the 2026 tax year are due April 15, 2026, June 15, 2026, September 15, 2026, January 15, 2027. Use Form K-40ES or pay online. The final installment for 2025 was due January 15, 2026.
Does Kansas accept the federal extension?
Yes. A federal extension is honored; no state form. The extended filing deadline is October 15, 2026, and tax is still due by April 15, 2026.
Does a Kansas extension give me more time to pay?
No. An extension extends the time to file, not to pay. To avoid penalties and interest, pay what you expect to owe by April 15, 2026.
Dates are the statutory deadlines that fall in 2026 and move to the next business day when they land on a weekend or holiday. Each section links to the source it was checked against. Always confirm with the Kansas tax agency or the IRS before relying on a date. This is general information, not tax advice.