Missouri's individual return is separate from federal Form 1040. At the time of writing, the Department of Revenue lists the 2025 MO-1040A, which you file in 2026. A 2026 annual return isn't listed. The 2026 document that is published, the MO-1040ES, covers estimated payments only.
This guide covers where to download the right form, who can use it, how to complete and file it, and the deadlines and penalties. All dollar figures are US dollars.
Key Takeaways
- The short form is MO-1040A. The full return is MO-1040.
- 2025 returns are due April 15, 2026. No 2026 annual form is listed yet.
- Credits, income modifications or income from both spouses require the full MO-1040.
- An extension moves the filing date, not the payment date.
- Check every number, sign the return and keep a copy.
What Is the 2026 MO-1040 Short Form?
The MO-1040A is Missouri's simplified "Single/Married (Income from One Spouse)" return. It reports your Missouri income, applies the standard or itemized deduction, calculates tax, counts withholding and payments, and shows a refund or balance due.
"MO-1040 short form" blends two names. MO-1040 is the long form, and MO-1040A is the short one. Use the A version if you qualify.
How it differs from other returns
- MO-1040A: simplified annual return for narrow, one-income situations.
- MO-1040: full return for credits, modifications, amendments and schedules.
- Federal Form 1040: a separate federal filing. Missouri asks for a copy of it, but filing federally doesn't mean the short form fits.
- MO-1040ES: the 2026 declaration of estimated tax, used for quarterly payments.
Download the Short Form and Instructions
Start at the Department of Revenue's official forms catalog. Avoid third-party PDFs, which are often outdated.
Download these from the 2025 entries:
- MO-1040A (fillable/calculating, or print-only)
- MO-1040A instructions
- MO-1040V payment voucher, if you owe tax
- MO-A, MO-CR, MO-NRI and MO-PTS only if your situation needs them (the short form excludes some of these filers)
- MO-60 if you need an extension and expect to owe
The tax chart and calculation worksheet sit inside the MO-1040A PDF. There is no separate tax table.
Saving and printing
- Download the PDF and open it in a desktop reader, not a browser tab. Browsers often drop typed entries.
- Use the fillable version if you want automatic calculations, then save it before closing.
- Print in black ink and don't staple. Check that all five pages came out.
- Confirm the tax year and revision date in the footer.
Missouri no longer prints and mails MO-1040 or MO-1040A forms, so you must download or print them yourself.
Prior-year and special versions
Older forms live in the same catalog under their year labels. They are not the current return. For amendments, use the MO-1040 long form with the amended-return box checked. The short form can't be used to amend. The catalog lists fillable and print-only versions. If you need large-print or Braille, contact the Department of Revenue for accessible formats.
If a 2026 form appears
Recheck the catalog before filing. A draft or a form labeled with a different year isn't what you want. The 2026 tax year runs through December 2026, so its return is filed in 2027.
Who Can Use the Missouri Short Form?
The 2025 instructions set the test. You can use the MO-1040A if you:
- Are single, or married with income from one spouse only
- Have only Missouri income, whether you are a resident, part-year resident or nonresident
- Claim the standard or an itemised deduction
- Claim no tax credits and no income modifications
Nonresidency alone doesn't disqualify you. Other-state income does.
What pushes you to the full return
The instructions expressly exclude:
- Both spouses with income
- Other-state income, military pay or a net operating loss
- Partnership, S-corporation or fiduciary adjustments
- Capital gains modifications, and certain 529, MOST and ABLE items
- Pension, Social Security, disability or military exemptions
- The property tax credit (MO-PTS) or the Working Family Tax Credit
- Underpayment penalty, fiscal-year filing, and several other special deductions
Business or rental income isn't excluded by name, but any adjustment or credit that comes with it is.
Which form should I use?
- Meet every MO-1040A criterion? Use the short form.
- Have credits, modifications or two incomes? Use the MO-1040 with the schedules you need.
- Have income taxed by another state? Look at MO-NRI or MO-CR, which attach to the MO-1040.
- Still unsure? Use reputable software or a professional.
How to Complete and File the Form
Gather your records
- Your federal return and W-2s or 1099s
- Records of Missouri withholding only (not federal, local or other-state withholding)
- Social Security numbers and dependent details
- Prior payments and bank routing and account numbers
- Itemised deduction records, if you itemise
Work through the form in order
Follow the form's sections: identification and filing status, income, deductions, tax from the chart or worksheet, payments, refund or balance due, and signature. Take line numbers from the form you actually downloaded, because they change between revisions.
Attach only what's required
Under the 2025 instructions, attach:
- Pages 1 and 2 of your federal return
- Federal Schedule A, if you itemise
- Copies of your W-2s and 1099s
Keep everything else for your records. For e-filing, Missouri says no paperwork is mailed, but you should retain copies in case the Department asks.
Choose a filing method
E-file: Use approved software, a tax preparer, or a Free File provider listed on the Department's site. Missouri follows IRS e-file signature procedures, and the old MO-8453 form is no longer used. State acceptance produces an acknowledgement, so save it.
Paper: Sign the return (both spouses sign a combined return) and mail it. The published mailing addresses conflict: the print-only and fillable 2025 short forms list different P.O. boxes for balance-due and refund returns.
Use the address printed on the exact form and instructions you downloaded, and check the Department's current guidance if unsure.
Payment: Pay by eCheck or card online, or by e-file bank debit. By mail, send a check or money order payable to Missouri Department of Revenue with the MO-1040V voucher. No cash. Direct deposit needs your routing and account numbers.
Final accuracy check
- Correct tax year and filing status
- SSNs and names match your records
- Income totals and withholding match your W-2s and 1099s
- Bank details are correct
- Signatures are in place and attachments are included
- Arithmetic is right, and the figures agree with your federal return
Some situations deserve a second pair of eyes: multistate income, business activity, unfiled prior years, or an agency notice. VJM Global's tax team prepares US federal and state returns for individuals and can review these cases. Confirm Missouri-specific practice authorisation separately if you need a local filing representative.
Missouri Deadlines, Extensions, Tax Rates, and Late Penalties
Deadlines
- 2025 return and payment: April 15, 2026.
- 2026 return: Missouri law sets the due date at the 15th day of the fourth month after year-end, so April 2027 as a baseline. Confirm the official date with the Missouri Department of Revenue when it is published.
- If the date lands on a weekend or Missouri legal holiday, it moves to the next business day. Disaster relief can shift dates for designated areas. In 2025, for instance, qualifying taxpayers received until November 3.
Extensions
For 2025 returns, a federal extension is recognized. File MO-60 if you expect to owe tax or want a Missouri-only extension. It is due by the original deadline. The extended filing date is October 15, 2026. Payment is not extended, so pay what you owe by April 15.
Rates and deductions
Missouri's top marginal rate is 4.7% in both published charts, but the thresholds differ by year.
| Item | 2025 | 2026 (estimated-tax chart) |
|---|---|---|
| 0% band ends at | $1,313 | $1,348 |
| 4.7% applies above | $9,191 | $9,436 |
| Standard deduction, single | $15,750 | $16,100 |
| Standard deduction, married combined | $31,500 | $32,200 |
| Standard deduction, head of household | $23,625 | $24,150 |
For a 2025 return, use the 2025 chart inside the MO-1040A. The 2026 figures come from the estimated-tax declaration, not an annual return.
Penalties and interest
- Late filing: 5% per month, up to 25% of the unpaid balance.
- Late payment: 5% of the unpaid balance.
- Interest: 8% for calendar 2025 and 7% for 2026 on deficiency balances.
- Estimated tax: The 2026 declaration is required if you expect to owe $100 or more. An underpayment penalty on a 2025 return means you must use the MO-1040 with Form MO-2210.
See the Department's individual income tax FAQs for the current penalty wording.
Frequently Asked Questions
What is the penalty for filing Missouri state taxes late?
Late filing costs 5% per month up to 25% of the unpaid balance, plus 5% for late payment. Interest applies on top. An extension does not extend the payment deadline.
What is the deadline for filing Missouri tax returns?
For the 2025 tax year, April 15, 2026. A 2026 return follows the same statutory rule, so expect April 2027. Weekends and Missouri holidays move the date to the next business day.
Can I get an income tax extension in Missouri?
Yes. A federal extension is recognised; file MO-60 if you expect to owe or need a Missouri-only extension. The extended 2025 filing date is October 15, 2026, but payment remains due April 15.
How do I file my 2026 tax return?
Use the form and instructions for the correct tax year, either by e-file through approved software or by mailing a signed paper return. Keep your acknowledgement or proof of mailing.
Can I download and print tax forms?
Yes, from the Department of Revenue's forms catalogue. Print in black ink, don't staple, and confirm the tax year and footer revision date. The Department no longer mails printed MO-1040 forms.
What does the MO 1040 short form look like?
The 2025 MO-1040A runs five pages. It covers filing status, income, deductions, tax or refund, signature, direct deposit, an itemised-deduction worksheet and the tax chart. Confirm the version before filing.
