Tax Planning & Concepts
When Are K-1s Due? Deadlines and Extensions
Schedule K-1s are due when the entity that issues them files its return. For a calendar-year partnership (Form 1065) or S corporation (Form 1120-S), the K-1 must reach each partner or shareholder by the 15th day of the third month after year-end, which is March 15. Because March 15, 2026 falls on a Sunday, the 2025 tax-year deadline shifts to March 16, 2026. If the entity extends with Form 7004, the K-1 deadline moves to September 15, 2026.
That single date drives a lot of frustration, because the people who need a K-1 to file their own return often get it days before, or weeks after, their personal deadline. This guide lays out every K-1 due date by entity type, explains why the forms run late, and gives you two clean options when yours does not arrive on time.
When Are K-1s Due in 2026?
For the 2025 tax year, K-1s from calendar-year partnerships and S corporations are due March 16, 2026 (the 15th falls on a Sunday). Estate and trust K-1s (Form 1041) are due April 15, 2026. Each date can be pushed roughly six months by a valid entity extension. The K-1 is due when the entity return is due, not on the recipient’s personal deadline.
The rule that sets every K-1 deadline is simple: the K-1 is part of the entity’s return, so it is due when that return is due. A partner does not get a separate, earlier K-1 date. That is why understanding the entity’s calendar matters more than your own.
| Entity / form | K-1 issued on | Original deadline (2025 tax year) | Extended deadline | Extension form |
|---|---|---|---|---|
| Partnership / LLC (Form 1065) | Schedule K-1 (1065) | March 16, 2026 | September 15, 2026 | Form 7004 |
| S corporation (Form 1120-S) | Schedule K-1 (1120-S) | March 16, 2026 | September 15, 2026 | Form 7004 |
| Estate or trust (Form 1041) | Schedule K-1 (1041) | April 15, 2026 | September 30, 2026 | Form 7004 |
| Individual recipient’s own return (Form 1040) | Reports the K-1 | April 15, 2026 | October 15, 2026 | Form 4868 |
Fiscal-year entities follow the same structure on a shifted calendar: the return, and therefore the K-1, is due the 15th day of the third month after the entity’s year-end (or the fourth month for estates and trusts). A June 30 year-end partnership, for example, owes K-1s by September 15.
The March 15 Entity Deadline
Calendar-year partnerships and S corporations must file Form 1065 or Form 1120-S, and furnish the related K-1s, by the 15th day of the third month after the tax year closes. For a December 31, 2025 year-end that is March 15, 2026, moved to March 16 because the 15th is a Sunday. Missing it triggers per-partner and per-statement penalties.
Two separate penalties can apply. The late-filing penalty for a partnership or S-corp return runs per partner or shareholder for each month the return is late. Separately, failing to furnish a correct K-1 to a recipient on time can cost the entity roughly $330 per statement for 2025 filings, rising to about $660 per statement if the failure is intentional. These are entity-level costs, not the recipient’s.
The March deadline exists so recipients have about a month to fold K-1 figures into their April 15 personal return. In practice, complex entities rarely finish on time, which is where the extension comes in.
The September 15 Extension
An entity that cannot finalize its return by March files Form 7004 to receive an automatic six-month extension, moving the partnership or S-corp K-1 deadline to September 15, 2026. Estates and trusts extend to September 30. The extension is automatic if filed on time, so no explanation to the IRS is required.
The catch for recipients: a September 15 entity extension lands after the April 15 individual deadline. If you are waiting on an extended K-1, you almost always need your own extension too. An entity extension does not extend your personal return, and it does not extend the time to pay any tax you owe. Estimated tax is still generally due by April 15.
Filing Form 7004 buys the entity time to file, not time to pay any entity-level tax (most pass-throughs owe none, but some state and composite obligations survive). The recipient’s payment clock is separate and still ends April 15.
Why K-1s Often Arrive Late
K-1s run late because the process is sequential: the entity must close its books, finalize the full return, and only then can it cut each K-1. Complex partnerships, tiered structures, real estate depreciation, foreign holdings, and late fund-administrator data can push issuance past the entity deadline into the September extension window.
Common drivers of delay include:
- Tiered ownership. A partnership that owns interests in other partnerships cannot finish until it receives K-1s from every lower-tier entity, creating a chain of dependencies.
- Investment funds. Private equity, venture, and hedge fund K-1s depend on fund-administrator exports and audited valuations that often are not ready until late summer.
- Complex adjustments. Depreciation changes, 1031 exchanges, basis calculations, and multi-state apportionment all require review before figures are final.
- Volume and staffing. Firms with hundreds of K-1s to produce during a compressed season frequently extend the entity return to preserve accuracy.
None of these are unusual. If you hold an interest in a fund or a multi-tier partnership, a K-1 arriving in August or September is closer to the norm than the exception.
What to Do If Your K-1 Is Late
If your K-1 has not arrived by early April, take one of two paths: file your own extension and wait for the form, or file on a good-faith estimate and amend later. The first is cleaner for most people. Either way, pay any tax you expect to owe by April 15 to avoid interest and late-payment penalties.
Follow this sequence:
- Confirm the entity’s status. Ask the issuer whether the entity has extended. If it filed Form 7004, your K-1 may not arrive until close to September 15, and you should plan around that, not April.
- File your own extension. Submit Form 4868 by April 15, 2026 to move your personal deadline to October 15, 2026. This is the standard move when a K-1 is outstanding.
- Pay your estimate now. An extension postpones filing, not payment. Estimate the tax tied to the expected K-1 income and pay it with the extension to stop interest and the late-payment penalty from accruing.
- Or file with a reasonable estimate. If you have prior-year K-1s, distribution records, or entity financials, you may file using a good-faith estimate and then file an amended return (Form 1040-X) once the final K-1 arrives. This carries amendment risk if figures shift materially.
Do not file a return leaving K-1 income off entirely. The IRS receives its own copy of every K-1, so omitted figures surface later as a mismatch notice. Extend and wait, or estimate and amend, but account for the income either way.
Frequently Asked Questions
When are K-1s due for the 2025 tax year?
Partnership and S-corporation K-1s for the 2025 tax year are due March 16, 2026, because the normal March 15 date falls on a Sunday. Estate and trust K-1s (Form 1041) are due April 15, 2026. If the entity files Form 7004, partnership and S-corp K-1s extend to September 15, 2026.
Can a partnership issue my K-1 after April 15?
Yes. If the partnership filed Form 7004, its return and your K-1 are not due until September 15, 2026, which is after the individual April 15 deadline. That timing is legal and common. When it happens, you generally file your own extension with Form 4868 and pay any estimated tax owed by April 15.
Does a K-1 extension extend my personal tax return?
No. An entity’s Form 7004 extension applies only to the entity, not to you. To move your personal deadline from April 15 to October 15, you must file your own Form 4868. Neither extension extends the time to pay; tax you owe is still generally due by April 15 to avoid interest and penalties.
What is the penalty if an entity issues K-1s late?
For 2025 filings, failing to furnish a correct K-1 on time can cost the entity about $330 per statement, or roughly $660 per statement if the failure is intentional. A separate late-filing penalty for the partnership or S-corp return applies per partner or shareholder for each month the return is late. These penalties fall on the entity, not the recipient.
Should I file my taxes without my K-1?
Only with a reasonable estimate, and generally the extension route is safer. If you have prior-year K-1s or entity financials, you may file using a good-faith estimate and amend with Form 1040-X after the real K-1 arrives. Filing while simply omitting K-1 income invites an IRS mismatch notice, because the agency receives its own copy of every K-1.
When are estate and trust K-1s due?
Estate and trust K-1s come from Form 1041, which is due the 15th day of the fourth month after the tax year ends, or April 15, 2026 for a calendar-year 2025 return. An extension moves the deadline about five and a half months, to September 30, 2026. Beneficiaries who need those figures for their own returns often extend to October 15.
Reviewed by The Ledgerism Editorial Team. Last reviewed: July 2026.
Related reading: Schedule K-1 explained, Form 1065, the partnership return, Form 1120-S, the S corporation return, Form 7004 business extensions, Form 4868 personal extensions, and estimated tax payments.