This guide covers U.S. federal partnership returns, mainly Form 1065. It is written for Australian businesses and other international owners with U.S. filing obligations. It does not cover Australian partnership tax rules, which are separate.
We walk through deadlines, the penalty calculation, Schedule K-1 exposure, IRS relief options and what to do after a notice arrives. Figures are in US dollars.
Key Takeaways
- A partnership must file a complete, timely Form 1065 even though income passes through to partners.
- Penalty = IRS rate × partners × months or part-months late, capped at 12 months.
- Extension, IRS acceptance and complete K-1 data all count toward timely filing.
- First-time abatement, reasonable cause and Rev. Proc. 84-35 each have separate requirements.
Understanding the Partnership Filing Obligation
What Form 1065 and Schedule K-1 report
Form 1065 reports the partnership's income, deductions, credits and allocations. Schedule K-1 then passes each partner's share to their own return. Under the IRS K-1 instructions, partners report their shares even without receiving distributions, and the partnership generally pays no income tax itself.
Who bears the penalty
The penalty is assessed against the partnership. The IRS can collect it from individual partners to the extent they are liable for partnership debts. Your partnership agreement decides how the cost is shared in practice.
Late versus incomplete or unaccepted
These are different failures:
| Condition | Treatment |
|---|---|
| Late | Not filed by the due date, including any valid extension |
| Incomplete | Missing information required under IRC 6031; penalised separately under IRC 6698 |
| Rejected or unaccepted e-file | Transmission alone is not enough; the IRS must acknowledge and accept the return |
A draft K-1 or a submitted transmission does not prove you filed. Keep the IRS acceptance record.
When Is a Partnership Return Due?
Calendar-year and fiscal-year partnerships
For a calendar-year partnership, Form 1065 is normally due 15 March. The 2025 return was due 16 March 2026 because of the weekend rule. Check the latest Form 1065 instructions for the current date.
Fiscal-year partnerships file by the 15th day of the third month after year-end. They do not follow the calendar-year date.
Extensions
File Form 7004 by the original due date. It generally gives six months to file, but no extra time to pay any tax due.
Partnerships that keep books and records outside the United States and Puerto Rico may qualify for an automatic extension under Regulation 1.6081-5, running to the 15th day of the sixth month. Attach the qualifying statement. Form 7004 can add a further three months to file. This exception may suit many Australian-run partnerships.
How the deadlines interact
- K-1s are due to partners by the partnership return deadline, including extensions.
- An individual partner's 2025 Form 1040 is generally due 15 April 2026, extendable to 15 October 2026 with Form 4868.
- Form 1040-NR is due 15 April if the partner received wages subject to U.S. withholding, otherwise 15 June.
- Extensions to file do not extend payment, and they do not remove Section 1446 withholding duties for foreign partners.
How Is the Late Filing Penalty Calculated?
The formula
Under IRC 6698, the penalty is:
Monthly rate × partners during any part of the tax year × months or part-months late (maximum 12)
The rate is inflation-adjusted:
| Tax year | Filing year | Per partner, per month |
|---|---|---|
| 2024 | 2025 | $245 |
| 2025 | 2026 | $255 |
| 2026 | 2027 | $260 |
Who counts as a partner
Anyone who was a partner for any part of the tax year counts, not only year-end owners. A partner who left in March still adds to the total.
The IRS rule treating spouses and estates as one partner applies to Rev. Proc. 84-35 eligibility. Whether any equivalent aggregation rule applies to the penalty calculation is unclear, so confirm with a preparer.
Worked example (hypothetical)
Take a partnership with four partners and a rate of $255 for illustration:
- One month late: $255 × 4 × 1 = $1,020
- Five months late: $255 × 4 × 5 = $5,100
- Twelve months or more: $255 × 4 × 12 = $12,240 (the cap)
Filing one day late counts as a full month.
Late and incomplete returns
IRM 20.1.2.4.1 says not to assess two IRC 6698 penalties. The incomplete-return penalty takes precedence unless the return is 12 months or more late. For a missing-information notice (CP162B), the penalty continues until the IRS receives the information, up to 12 months.
Can the IRS Waive or Abate the Penalty?
First-time abatement
First-time abatement (FTA) covers late filing under IRC 6698(a)(1). The IRS reviews the same return type for the preceding three years. A clean history supports relief, while earlier penalties or a prior FTA can block it.
From tax year 2025, Automatic Exemption from Penalty (AEP) replaces FTA for eligible originals due from 1 January 2027. It requires timely filing and payment in the three prior years.
Reasonable cause
You must show ordinary business care and prudence despite being unable to comply. Examples include:
- Death or serious illness
- Natural disaster
- Unavoidable absence
- Records that were inaccessible
Handing filing to someone else is generally not reasonable cause, so keep thorough records of what prevented timely compliance.
Rev. Proc. 84-35 for small partnerships
This is a reasonable-cause pathway, not a filing exemption. Small partnerships must still file Form 1065. The conditions are:
- 10 or fewer partners, with spouses and their estate counting as one
- All partners are natural persons or qualifying deceased-partner estates
- Nonresident aliens, trusts and corporate partners do not qualify
- Allocations use the same proportion across all items
- Every partner reported their share on a timely filed return
The IRS memorandum on this procedure describes a case where partners reported years late and relief failed. Because a nonresident alien partner fails the test, most Australian-owned partnerships will not qualify.
Relief-request checklist
- Read the notice and note the tax period and penalty amount.
- File any missing returns.
- Build a factual timeline.
- Gather supporting records.
- Respond by the method the notice specifies: by phone, in writing, or with Form 843.
What to Do After Filing a Partnership Return Late
File a complete, accurate return immediately. Waiting for a relief decision adds months to the penalty until the 12-month cap.
Confirm IRS acceptance
- Get the acknowledgement showing Accepted, with the IRS received date.
- Fix rejected returns quickly. Rejected business returns have a 10-calendar-day window to perfect and keep the original received date.
- Confirm all schedules and K-1 data were included.
- E-file is required for partnerships with more than 100 partners or 10 or more returns of any type.
K-1 penalties are separate
K-1 failures fall under IRC 6722, which can apply alongside the Form 1065 penalty. The 2026 per-statement tiers are $60, $130 and $340, with intentional disregard at $680 or more.
Prevention checklist
- Set calendar reminders ahead of 15 March
- Track extension filing and acceptance
- Record partner changes during the year
- Collect documents early
- Review every K-1 before issuing
- Confirm federal and state filings were accepted
Getting help
Australian businesses with US partnership obligations can turn to VJM Global for US-compliant return preparation, compliance review and IRS notice support. If a notice arrives, an authorised partner can call 800-829-0922 using the CP162A or CP162B guidance. A written appeal after a denial generally has a 30-day window.
Frequently Asked Questions
What is the penalty for late filing a partnership tax return?
It depends on the IRS rate for the tax year, the number of partners and months or part-months late. For 2025 returns the rate is $255 per partner per month.
How is the failure to file penalty calculated?
Multiply the applicable rate by the number of partners during any part of the year, then by the months or part-months late. The total is capped at 12 months.
What is the deadline for a partnership return?
Calendar-year partnerships file by 15 March, adjusted for weekends and holidays. Fiscal-year partnerships file by the 15th day of the third month after year-end. File Form 7004 before the original date to extend.
What is the penalty for filing a K-1 late?
K-1 failures fall under IRC 6722, separate from the Form 1065 penalty. For statements due in 2026, tiers run from $60 to $340 per statement.
Will the IRS waive late filing penalties?
Yes, in some cases through first-time abatement, reasonable cause or Rev. Proc. 84-35. Approval depends on eligibility and documentation.
What counts as a failure to file?
Filing Form 1065 after the due date including extensions, or omitting required information. Reasonable cause can excuse either.
