"2026" can mean two things. Most readers want the 2025 return filed in 2026, which is the latest MO-1065 the Missouri Department of Revenue (DOR) has posted. A 2026 tax-year return filed in 2027 will use a form not yet released, so its rates and line changes can't be confirmed.
This guide covers filing obligations, deadlines, extensions, Missouri adjustments, schedules, payments, filing methods, and common mistakes. The current DOR instructions always control.
Key Takeaways
- File MO-1065 when federal Form 1065 is required and a Missouri resident partner or Missouri-source income exists.
- Calendar-year 2025 returns were due April 15, 2026; a granted federal Form 7004 extends the Missouri deadline automatically.
- Apply Missouri additions, subtractions, and allocations to federal figures before filing the state return.
- Nonresident partners may trigger MO-1NR withholding or a composite return.
What Is Form MO-1065 and Who Must File It?
What the form reports
MO-1065 reports the partnership's income, deductions, Missouri adjustments, and partner allocations. DOR treats it as informational: income flows through to the partners, who pay tax on their own returns. The entity-level tax option is a separate election on Form MO-PTE.
Complete the federal Form 1065 first. The Missouri return covers the same tax period, and federal amounts feed into it. But Missouri has its own additions and subtractions, so copying federal numbers line for line is a mistake.
Who must file
According to the 2025 MO-1065 instructions, you file when a federal Form 1065 is required and the partnership has a Missouri-resident partner or Missouri-source income. State law (RSMo 143.581) uses the same two triggers.
- The form expressly names LLCs taxed as partnerships.
- Check the current instructions for how DOR treats general partnerships, limited partnerships, and LLPs.
- There is no general income-dollar threshold.
- A zero-income statement alone doesn't excuse a partnership that has a Missouri-resident partner.
Final and amended returns use checkboxes on the form. Fiscal-year partnerships enter their beginning and ending dates when the year isn't a calendar year.
Who prepares and signs
The partnership is responsible for the return. Any partner or joint-venture member may sign, regardless of position. A paid preparer adds a signature and an FEIN, SSN, or PTIN. Individual partners don't sign the MO-1065, but they receive their share of the information for their own returns.
MO-1065 Due Dates, Extensions, Payments, and Penalties
Finding the right filing period
A calendar-year partnership files its 2025 return in 2026. A fiscal-year partnership files on a date tied to its own year-end, which may also fall in 2026.
The rule is the same for both: the due date is the 15th day of the fourth month after the tax year closes.
| Year-end | Missouri due date |
|---|---|
| December 31, 2025 | April 15, 2026 |
| June 30, 2025 | October 15, 2025 |
| September 30, 2025 | January 15, 2026 |
If the date lands on a Saturday, Sunday, or legal holiday, filing on the next business day is timely.
Missouri versus federal
Federal Form 1065 is generally due the 15th day of the third month. For calendar-year 2025, the IRS instructions put that at March 16, 2026, because March 15 fell on a weekend. Missouri's deadline came a month later. Don't assume the two always line up.
Extensions
A granted federal Form 7004 automatically extends the Missouri partnership filing period. Attach a copy of the filed or approved Form 7004 to the Missouri return. The 2025 instructions don't describe a separate Missouri-only MO-1065 extension form.
Related extensions work differently:
- MO-1NR nonresident withholding follows the partnership's original or extended due date.
- A federal extension can also extend MO-PTE filing, but the tax must be paid by the extended date to avoid a 5% addition.
- Composite returns have their own extension instructions, and Form MO-60 may apply.
Payments and partner-level obligations
Because MO-1065 is informational, it has no payment voucher of its own. Money changes hands through other filings:
- MO-1NR/MO-2NR: withholding on nonresident partners. For tax year 2025 the rate was 4.70% of a covered partner's Missouri-source distributive income.
- Composite return: covers eligible nonresident partners who wouldn't otherwise file, under the partnership's name and EIN.
- MO-PTE: an annual election to pay entity-level tax, at 4.7% of the specified net amount for 2025. The election can't be revoked for that year.
The 2025 withholding exceptions include an eligible composite election, Missouri-assignable federal AGI under $1,200, and a filed MO-3NR exemption agreement. Confirm tax-year 2026 withholding and MO-PTE rates with DOR before you file, as they may differ from 2025.
Late filing, interest, and relief
State law (RSMo 143.741) sets a failure-to-file penalty of 5% per month or fraction, capped at 25%, based on tax required to be shown. It includes a reasonable-cause exception. Whether that penalty reaches an informational return showing no tax is unclear, so confirm with DOR or a professional before assuming a number.
Interest applies to unpaid Missouri tax balances. DOR's 2026 table lists 7%. Missouri penalties are separate from IRS penalties, so a late federal return and a late state return can each generate their own notices.
Step-by-Step Form MO-1065 Instructions
Gather your records
Pull these together before you start:
- The completed federal Form 1065 and all Schedules K-1
- Trial balance, income statement, and balance sheet
- Last year's Missouri return
- Partner ownership percentages, addresses, and residency
- Missouri-source income and multistate apportionment data
- Any extension, withholding, or composite payment confirmations
Enter the return identification
Fill in the legal name, FEIN, address, tax year, and any amended or final-return box. If details changed since last year, use the current ones, and make sure they match the federal return. A mismatch is a common reason for correspondence.
Report income and Missouri adjustments
Start from federal figures, then apply Missouri changes. Examples in the 2025 form include:
- Additions: state and local income taxes deducted federally, and interest on non-Missouri state and local bonds.
- Subtractions: interest from exempt federal obligations, state income-tax refunds included in federal income, and the Missouri depreciation-basis adjustment.
- An agriculture-disaster-relief line.
Treat these as examples. Work from the line-by-line instructions for your return year, not from memory.
Allocate among partners
The form's partner allocation schedule applies each partner's federal K-1 percentage, rounded to the nearest whole number, to the total Missouri adjustment. Slow down on nonresident partners, ownership changes, guaranteed payments, and multistate operations. If you have a tiered partnership, confirm the treatment with DOR, since the form instructions do not set out a specific rule.
Review, sign, and submit
- Confirm the math and that totals tie to the federal return.
- Verify partner percentages add up and every partner is listed.
- Attach required schedules and, where required, the federal Form 1065 with K-1s.
- Attach the federal Form 7004 copy if you extended.
- Sign, add preparer details, then file.
Required Schedules, Missouri Adjustments, and Filing Methods
Schedules and attachments
The 2025 form uses two questions to decide what goes with it:
- Both answers No: attach the federal Form 1065 and its schedules, including K-1s
- Yes to question 1: complete Parts 1 and 2
- Yes to question 2: attach Form MO-NRP
A standalone Missouri K-1 is not set out in the 2025 materials, so partners generally rely on the federal K-1 plus Missouri allocation information.
Apportionment and Missouri-source income
Form MO-NRP lists the categories compared against Missouri-source amounts: ordinary business income, rental income, guaranteed payments for services, portfolio income, and section 1231 gain. Business carried on only in Missouri is wholly Missouri-source. For multistate businesses, use direct allocation when records clearly show a Missouri source. Otherwise, apportion using the receipts factor from Form MO-MSS Part 1, line 3. Using any other method requires a detailed explanation.
Nonresident and multistate partners
Complete MO-NRP and give each nonresident partner a copy or its information. For withholding, MO-1NR requires a MO-2NR statement per covered partner. Partners who qualify can instead join a composite return. Not every partnership has the same obligation, so match your partner list against the exceptions above.
Reconcile partner-level reporting to the MO-1065 before filing. Get professional review when residency is mixed or the sourcing isn't obvious.
E-filing and paper filing
Partnerships may file electronically through the joint federal/state MeF program using DOR-approved providers. The 2025 instructions don't state a mandate, threshold, or waiver, so confirm current requirements for your year.
Addresses vary by filing, so don't send everything to one place:
| Filing | Address |
|---|---|
| MO-1065 paper return | Missouri Department of Revenue, P.O. Box 3000, Jefferson City, MO 65105-3000 |
| MO-1NR/MO-2NR withholding payment | Taxation Division, P.O. Box 555, Jefferson City, MO 65105-0555 |
| MO-PTE return or payment | P.O. Box 3080, Jefferson City, MO 65105-3080 |
| Composite return, no balance due | Individual Income Tax, P.O. Box 500, Jefferson City, MO 65106-0500 |
| Composite return, balance due | Individual Income Tax, P.O. Box 329, Jefferson City, MO 65107-0329 |
Verify against the current instructions before mailing.
Common mistakes
- Filing under the wrong tax year or confusing the federal and Missouri forms
- Leaving out required state schedules
- Missing nonresident partners
- Partner totals that don't match the federal K-1s
- Mailing to an outdated or wrong address
- Submitting an unsigned return
- Forgetting the amended or final box
Keep the filed return, federal return, worksheets, partner statements, payment confirmations, and e-file acceptance. The IRS says partnership records supporting return items generally should be kept for 3 years. Confirm any Missouri-specific MO-1065 retention period with the Department of Revenue, and keep records at least as long as the federal rule.
MO-1065 Filing Checklist and Professional Support
Run through this before you submit:
- Entity type and Missouri filing trigger confirmed
- Correct tax year and form version
- Federal return completed
- Missouri additions, subtractions, and apportionment applied
- Partner names, percentages, and residency verified
- Nonresident withholding or composite handled
- Schedules attached
- Federal Form 7004 copy attached, if extended
- Signatures and preparer details complete
- Filing method chosen, confirmation saved, records retained
Bring in a professional when you face:
- Multistate operations
- Nonresident or foreign partners
- Complex Missouri adjustments
- Amended or late returns
- Incomplete books or ownership changes
- Any state notice
VJM Global supports U.S.-based and multinational businesses with accounting, tax compliance, and financial support. Its team prepares Form 1065, Form 1120, Form 1040, and other federal and state filings.
Clients get experienced accounting professionals, secure data handling, and personalized assistance. VJM Global does not operate a Missouri office.
Frequently Asked Questions
How much does it cost to file a 1065?
Cost varies with the number of partners, bookkeeping quality, nonresident or multistate issues, state filings, and whether a professional prepares it. Request a quote based on your specific facts, as fees are not standardised.
What is the deadline for filing a partnership return?
For a calendar-year 2025 return, Missouri's MO-1065 deadline was April 15, 2026, a month after the federal March 16, 2026 date. A granted federal Form 7004 extends the Missouri deadline automatically.
Who fills out a 1065?
The partnership is responsible for the return. A responsible partner, employee, or tax professional may prepare it, and any partner or member may sign. Paid preparers add their own identification.
What is the address to mail a Missouri state income tax return?
The 2025 MO-1065 instructions list P.O. Box 3000, Jefferson City, MO 65105-3000. Payments, composite returns, and MO-PTE filings go to different addresses, so check the current instructions.
Is Form MO-1065 the same as federal Form 1065?
No. They are separate returns. The federal return supplies the starting figures, but Missouri adds its own adjustments, schedules, and allocations.
Do I need to file Form MO-1065 if my partnership had no income?
Possibly. Filing can still be required if you have a Missouri-resident partner or Missouri-source income. Confirm any zero-income rules in the current instructions or with DOR.
