Missouri 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 Missouri 2025 →
Missouri 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.
Missouri estimated tax payments in 2026
You must file a declaration of estimated tax if your Missouri estimated tax (tax less allowable credits and withholding) is expected to be $100 or more.
| 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 MO-1040ES |
| Underpayment safe harbor | No addition to tax if each installment is paid on time and total payments equal or exceed the tax shown on the preceding year's 12-month return or 90% (66 2/3% for farmers) of the current-year tax. |
| Pay online | dor.mo.gov |
Farmers with at least two-thirds of estimated Missouri gross income from farming may file and pay in one installment by January 15 or file the return and pay in full by March 1. The January 15 declaration is not required if you file a voucher and pay by January 31.
Source: dor.mo.gov, read September 3, 2026. “Your estimated tax may be paid in full with the first declaration voucher, or in equal installments on or before April 15, June 15, September 15, and January 15.”
All 51 jurisdictions in one table: state estimated tax payment dates for 2026.
Missouri extensions
Every state's rule in one table: which states accept the federal extension in 2026.
| Does Missouri accept the federal extension? | Yes. A federal extension is honored; no state form. |
|---|---|
| State extension form | Form MO-60 |
| 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. An extension does not extend the time to pay; additions to tax of 5% plus interest apply to tax not paid by the original due date. |
| How to get it | If you have a federal extension and expect no additional tax (or a refund), enclose a copy of the federal extension with the Missouri return; file Form MO-60 with payment only if you owe or want a Missouri-only extension. |
Source: dor.mo.gov, read September 3, 2026. “Missouri grants an automatic extension of time to file to any individual, business filing a composite return, or fiduciary if you filed a federal extension.”
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 Missouri state taxes due in 2026?
Your 2025 Missouri 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 Missouri estimated tax payments due in 2026?
Missouri estimated payments for the 2026 tax year are due April 15, 2026, June 15, 2026, September 15, 2026, January 15, 2027. Use Form MO-1040ES or pay online. The final installment for 2025 was due January 15, 2026.
Does Missouri accept the federal extension?
Yes. A federal extension is honored; no state form. The state form is Form MO-60. The extended filing deadline is October 15, 2026, and tax is still due by April 15, 2026.
Does a Missouri 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 Missouri tax agency or the IRS before relying on a date. This is general information, not tax advice.