Deadlines
Form 1065 due date: the partnership tax deadline for 2026 and 2027
Form 1065 is due on the 15th day of the 3rd month after the partnership's tax year ends: March 15 for calendar-year partnerships, moved to March 16, 2026 for 2025 returns. Fiscal-year dates, the September 15 extended date, K-1 timing and the penalties.
Prepared by Aldro Accounting · Updated · Sources checked
The quick answer
The IRS says a domestic partnership must file Form 1065 by the 15th day of the 3rd month after its tax year ends, which is March 15 for a calendar-year partnership. Because March 15, 2026 was a Sunday, 2025 returns were timely through March 16, 2026. Form 7004, filed by the due date, gives 6 more months, and a late Form 1065 costs $255 per partner for each month late, up to 12 months.
The rule: 15th day of the 3rd month
Generally, a domestic partnership must file Form 1065 by the 15th day of the 3rd month after the date its tax year ended. For calendar-year partnerships, that is March 15.
If the due date falls on a Saturday, Sunday or legal holiday in the District of Columbia or the state where the return is filed, a return filed the next business day is treated as timely. That's why the IRS says calendar-year partnerships could timely file their 2025 returns by March 16, 2026. Under the same rule, March 15, 2027 is a Monday, so it is the date for 2026 calendar-year returns.
Scroll sideways to see all columns.
| Tax year ends | Form 1065 and K-1s due | With Form 7004 (6 months) |
|---|---|---|
| December 31, 2025 | March 16, 2026 (March 15 was a Sunday) | September 15, 2026 |
| December 31, 2026 | March 15, 2027 | September 15, 2027 |
| March 31 | June 15 | December 15 |
| June 30 | September 15 | March 15 |
| September 30 | December 15 | June 15 |
This hasn't always been the date. For tax years beginning after December 31, 2015, the partnership due date became the 15th day of the 3rd month, and the automatic extension grew to six months.
Schedule K-1s are due the same day
IRS Publication 509 says a partnership provides each partner with a copy of their Schedule K-1 (Form 1065), and Schedule K-3 if it applies, by the 15th day of the 3rd month after the end of the partnership's tax year. With an extension, the K-1s follow the return.
Partners' own returns are due later. Form 1040 is due on the 15th day of the 4th month, so a partnership that extends to September pushes its partners' K-1s past their April deadline.
Getting more time: Form 7004
Form 7004 is used to request an automatic 6-month extension of time to file Form 1065. File it by the regular due date of the partnership return. It can be filed electronically, and no signature is required.
Partnerships that keep their books and records outside the United States and Puerto Rico get an automatic extension to the 15th day of the 6th month after year end without filing Form 7004.
Who has to meet the deadline
Form 1065 is an information return. Generally, a partnership doesn't pay tax on its income but passes profits or losses through to its partners. Every domestic partnership must file unless it neither receives income nor has expenditures treated as deductions or credits. A domestic LLC with at least two members that doesn't file Form 8832 is a partnership and files the same way.
A partnership that ends its operations has a short final year. Its tax year ends on the date of termination, the date it winds up its affairs, and that date starts the 3-month clock.
Partnerships that file 10 or more returns of any type during the tax year, or that have more than 100 partners, must file Form 1065 electronically.
What a missed deadline costs
Because a partnership usually owes no income tax itself, its late filing penalty isn't a percentage of tax. It is $255 for each month or part of a month the return is late or incomplete, up to 12 months, multiplied by the number of people who were partners at any time during the year.
A separate penalty applies to the K-1s: $340 for each K-1 (or K-3) not furnished on time or with missing or incorrect information. For all such failures in a calendar year, the maximum is $1,366,000 for entities with gross receipts of $5,000,000 or less, and $4,098,500 above that. Intentional disregard raises each penalty to $680, or 10% of the items required to be reported if greater, with no maximum.
Don't attach a reasonable-cause explanation to a late return. If a penalty notice arrives, the partnership can send an explanation then. Reasonable cause is presumed for certain small partnerships, which must have 10 or fewer partners and meet other criteria, under Rev. Proc. 84-35.
Aldro prepares and files Form 1065, each partner's K-1 and Form 7004 when it's needed, for one flat yearly price that covers everything tax.
Worked example
A four-partner LLC files its 2025 Form 1065 on May 20, 2026 without having filed Form 7004. Counting from March 16, 2026, the return is two months and part of a third late, so the penalty is $255 x 4 partners x 3 months = $3,060. If its four K-1s also went out late, add $340 x 4 = $1,360, for $4,420 in total. A Form 7004 filed by March 16 would have moved both deadlines to September 15, 2026.
Common questions
When is Form 1065 due?
By the 15th day of the 3rd month after the tax year ends: March 15 for calendar-year partnerships. For 2025 returns it was March 16, 2026, because March 15 fell on a Sunday.
When is the partnership tax deadline with an extension?
Form 7004 gives an automatic 6 months, so September 15 for a calendar-year partnership. It must be filed by the original due date.
When do partners get their K-1s?
By the same date as Form 1065: the 15th day of the 3rd month after year end, or the extended date if the partnership filed Form 7004.
Does a multi-member LLC have the same Form 1065 deadline?
Yes. A domestic LLC with at least two members that doesn't file Form 8832 is a partnership and has the same filing requirements.
What is the penalty for filing Form 1065 late?
$255 per partner for each month or part of a month late, up to 12 months, for 2025 returns. Late or wrong K-1s add $340 each.
The cheapest way to get your business taxes done: $399 flat.
Business tax filing is $399 USD a year, and it covers everything tax for that year.
How it works
- Tell us about your business. A two-minute form. No payment is collected through it.
- Get your next steps by email. We’ll email you the next steps within one business day. After you sign up we’ll send you a secure upload link for your documents.
- We file it. Our team prepares and files your return. Add bookkeeping for $20 a month if you want it.
What's included
$399 a year covers everything tax for that tax year.
- Every business return for the year. All the federal and state or provincial business returns you need for the tax year: Schedule C, 1065, 1120-S, 1120 and their state returns in the US; T2, or T1 with T2125, in Canada.
- More than one state. Multi-state returns are included at the same price.
- Your personal return. The owner’s personal return (1040 or T1) is included when it’s needed for the business income.
- Quebec. Quebec returns (CO-17, TP-1 and TP-80) are included. Our Quebec pages are in French, and our team works with you in English.
- Extensions and reminders. Extensions (Form 7004 or 4868) and quarterly estimate reminders are included.
- Information returns. 1099-NEC, T4/T4A and T5018 slips are included in the tax price.
- City and excise returns. City and local business tax returns, and state excise returns such as Washington B&O, are included in the yearly price.
- Franchise tax reports. State franchise tax reports, such as the Texas franchise tax report, are included.
- Estimated tax and instalment amounts. We work out your quarterly estimated tax payments in the US, or your CRA instalments in Canada, and tell you what to pay and when.
- Unfiled past years. Each unfiled prior-year return is $399 per tax year, the same flat price.
- Bookkeeping at $20 a month. Unlimited bank and card accounts, monthly reconciliation and monthly statements.
Basic inventory tracking for online stores, such as Shopify, is included. Full cost-of-goods reconciliation is quoted separately. Payroll processing and sales-tax filing aren’t included in bookkeeping. Prices are in USD. Our team prepares and files your return.
Sources
- IRS: Instructions for Form 1065 · checked October 31, 2026
- IRS: Publication 509, Tax calendars · checked October 31, 2026
- IRS: Instructions for Form 7004 · checked October 31, 2026
- IRS: Internal Revenue Manual 21.7.4 · checked October 31, 2026
- IRS: Failure to file penalty · checked October 31, 2026
This guide explains general rules from the sources listed. It isn’t tax advice for your situation.