Answer (2026 tax year): A calendar-year partnership (Form 1065) or S corporation (Form 1120-S) has to furnish your 2026 Schedule K-1 by Monday, March 15, 2027. If it files an extension, the deadline moves to Wednesday, September 15, 2027. A trust or estate (Form 1041) has until Thursday, April 15, 2027, or Thursday, September 30, 2027 on extension. Your own return is due April 15, 2027, so a K-1 from an extended entity can arrive on time and still land after your filing deadline.
Context: This guide is for households with more than one K-1: a fund or two, a real estate partnership, a family LLC, an S corporation, a trust. The question that matters is less "when is it due" than "which ones are still out, and what does my CPA need from me while I wait."
Updated for the 2026 tax year (filed in 2027). Last reviewed: September 30, 2026.
- The K-1 deadline follows the entity's own return deadline, including extensions. An extended partnership that delivers your K-1 on September 15, 2027 is on time.
- March 15, 2027 is a Monday, so there's no weekend shift this year. (For the 2025 tax year the date moved to March 16, 2026, because March 15 fell on a Sunday.)
- The squeeze comes at the end of the season. Your personal extension runs to October 15, 2027, which leaves one month after an extended partnership K-1 and about two weeks after an extended trust K-1.
- An extension gives you more time to file, not more time to pay.
- Check who the K-1 is made out to. A K-1 addressed to your trust or your LLC may belong on a different return than yours.
These dates apply to calendar-year entities. The tax year is printed at the top of each K-1, so last year's K-1 tells you which kind you hold.
| Who issues the K-1 | Return it comes with | K-1 due to you | If the entity extends |
|---|
| Partnership or multi-member LLC | Form 1065 | Monday, March 15, 2027 | Wednesday, September 15, 2027 |
| S corporation | Form 1120-S | Monday, March 15, 2027 | Wednesday, September 15, 2027 |
| Trust or estate | Form 1041 | Thursday, April 15, 2027 | Thursday, September 30, 2027 |
| Your own return | Form 1040 | Thursday, April 15, 2027 | Friday, October 15, 2027 (Form 4868) |
Where these come from:
- Partnerships. Form 1065 is due the 15th day of the 3rd month after the tax year ends, and the partnership has to furnish each partner's K-1 on or before the day its return is due, counting extensions. A Form 7004 extension adds six months.
- S corporations. Same 15th day of the 3rd month rule. The IRS instructions say each shareholder's K-1 must be provided on or before the day Form 1120-S is required to be filed.
- Trusts and estates. Form 1041 is due the 15th day of the 4th month, and the fiduciary has to provide K-1s by the same day. The automatic extension for Form 1041 is five and a half months, which runs to September 30.
- Weekends and holidays. When a due date falls on a Saturday, Sunday, or legal holiday, the next business day counts as on time. None of the 2027 dates above land on one.
A fiscal-year entity uses the same month counts from the end of its own year, so its dates will differ. The 2026 instructions for these forms usually publish in December or January. The IRS draft 2026 K-1 forms released so far keep the same layout as 2025.
Most people treat March 15 as K-1 day. For a household with private funds or real estate partnerships, the useful date is later.
An extension is easy for a partnership to get, and an extended partnership has until September 15, 2027 to deliver your K-1. That's fully on time. If you also hold a trust interest, an extended trust K-1 can arrive September 30. Your own extended return is due October 15. So in a heavy year, the last K-1 can show up two weeks before your final deadline, and your CPA still needs time to put it on the return.
The practical question each spring, then, is whether this issuer extended, and when it expects to send the K-1. You can simply ask. The template below does.
A K-1 is a page of the entity's own tax return. The entity can't finish your K-1 until it finishes its return, and several things push that back:
- The entity is waiting on K-1s of its own. A fund that invests in other partnerships, or a real estate partnership that owns property through several LLCs, needs the numbers from each of those before it can close its books. Every tier adds weeks.
- Extensions are automatic. Filing Form 7004 gets the entity six more months (five and a half for a trust), and the K-1 deadline moves with it. An issuer that needs more time has an easy way to take it.
- International reporting adds work. A partnership with foreign activity, or foreign partners, may have to prepare Schedule K-3 alongside the K-1. See the K-1 checklist for your CPA for how K-3s work.
- Corrections happen. If the entity finds an error after sending K-1s, it may issue an amended K-1 (or, for many partnerships, a later Form 8986), which restarts your CPA's work on that item.
- The entity doesn't have current details. A new address, a partnership interest moved into a trust, a partner who died: any of these can send a K-1 to the wrong place or the wrong name.
A K-1 goes to the partner of record, which isn't always you. Part II of the partnership K-1 shows the partner's name and taxpayer ID. If a single-member LLC that's disregarded for tax holds the interest, item H2 names that entity alongside the owner. If your revocable trust, an irrevocable trust, or a family partnership holds the interest, the K-1 is made out to it.
This matters for timing because it changes whose return the K-1 feeds and which deadline it's racing. A K-1 to a non-grantor trust feeds the trust's Form 1041, and then the trust may issue its own K-1 to beneficiaries. (Some irrevocable trusts are grantor trusts, whose items are reported by the grantor instead. Your CPA determines which applies.) Each layer waits on the one below it. When you're listing what's still out, list it by owner: you, your spouse, each trust, each entity.
1. Check whether it's late at all. Before March 15, 2027 (or April 15 for a trust), it isn't. After that, the first question is whether the entity extended. If it did, the K-1 is on time until September 15 or September 30.
2. Ask the issuer. The investor relations team, fund administrator, general partner, or trustee can usually tell you whether they extended and when they expect to send K-1s. Use the note below.
3. Decide on your own extension with your CPA. Filing Form 4868 by April 15, 2027 gives you until October 15, 2027 to file. It doesn't extend the time to pay: interest runs on any tax not paid by April 15, and a late payment penalty can apply. An extension can go in with an estimated payment, and how much to pay is a CPA question, since it depends on last year's numbers and what the missing K-1s are likely to show.
4. Filing on an estimate is another option. Some households file by April 15 using the best information they have and file Form 1040-X when the final K-1 arrives. A return filed on estimates because a K-1 hasn't arrived may need Form 8082 to disclose that. Whether this approach fits your return is a CPA decision.
5. Corrections come from the issuer. If a K-1 arrives with a mistake, such as the wrong name, the wrong taxpayer ID, or the wrong year, the IRS partner instructions say to ask the partnership for a corrected K-1 rather than change your copy.
6. Keep one list of what's still out. By issuer, by owner, and with a date for your last follow-up. That list is what your CPA asks for in March, and again in September. Last year's Schedule E, Part II is a good place to start: it lists each partnership and S corporation that sent you a K-1, with its employer identification number.
Copy this, fill in the brackets, and send it to the contact on last year's K-1 or the fund's investor portal.
Subject: 2026 Schedule K-1 for [name on last year's K-1]
Hello,
[Name on last year's K-1] holds an interest in [entity name]. Our 2026 K-1 hasn't arrived yet, and our CPA is planning around it. Could you tell us:
- Has [entity name] filed an extension for its 2026 return, and when do you expect to send 2026 K-1s?
- Where will the K-1 be delivered (portal, email, or mail), and do you have our current name, address, and taxpayer ID on file?
- Will a Schedule K-3 be included, or do we need to request one?
- Do you provide estimated 2026 amounts before the final K-1? If so, please send them when available.
Our CPA is [name, firm, email]. Please copy them when the K-1 is issued, if you're able to.
Thank you,
[Your name]
[Phone]
A few notes on using it. Send it from the email address the issuer has on file, since an issuer may not discuss an account with an address it doesn't recognize. If the interest is held by a trust or an LLC, write as the trustee or manager and use the entity's name. And if you've been told K-1s go out "after the fund's return is final," ask for a month. A month is something your CPA can plan around.
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When are K-1s due for the 2026 tax year?
Partnership and S corporation K-1s are due Monday, March 15, 2027, or Wednesday, September 15, 2027 if the entity extends. Trust and estate K-1s are due Thursday, April 15, 2027, or Thursday, September 30, 2027 on extension. These dates are for calendar-year entities.
Is the 2027 K-1 deadline March 15 or March 16?
March 15, 2027. It falls on a Monday, so it doesn't move. The March 16 date applied to the 2025 tax year, when March 15, 2026 was a Sunday.
Can a K-1 legally arrive after April 15?
Yes. A partnership or S corporation that files an extension has until September 15, 2027 to furnish K-1s for the 2026 tax year, and an extended trust or estate has until September 30, 2027. Your own return can be extended to October 15, 2027.
Can I file my taxes without a K-1?
You can file Form 4868 by April 15 to extend your filing deadline to October 15, or file on your best estimate and amend later with Form 1040-X. A return filed on estimates because a K-1 hasn't arrived may need Form 8082 to disclose that. Which approach fits your return is a question for your CPA.
Does an extension give me more time to pay?
No. Form 4868 extends the time to file, not the time to pay. Interest accrues on any tax not paid by April 15, 2027, and a late payment penalty can apply.
Is there a penalty if a partnership sends my K-1 late?
The IRS can charge the partnership a penalty for each K-1 it fails to furnish on time, and the same applies to S corporations and trusts. The penalty falls on the entity, not on you.
- IRS: Instructions for Form 1065 (2025), When To File, Extension of Time To File, and Failure To Furnish Information Timely
- IRS: Partnership Instructions for Schedules K-2 and K-3 (Form 1065) (2025), K-1s furnished "on or before the due date (including extensions) for the partnership return"
- 26 CFR 1.6031(b)-1T(b), time for furnishing the partner statement, determined with regard to extensions
- IRS: Instructions for Form 1120-S (2025), due date and when Schedule K-1 must be provided
- IRS: Instructions for Form 1041 and Schedules A, B, G, J, and K-1 (2025), When To File, Extension of Time To File, and Failure To Provide Information Timely
- IRS: Instructions for Form 7004 (Rev. December 2025), six-month extension, five and a half months for Form 1041
- IRS: Form 4868 (2025), six-month filing extension, interest and late payment penalty
- IRS: Instructions for Form 8082 (Rev. October 2025), K-1 not received by the filing date
- IRS: Partner's Instructions for Schedule K-1 (Form 1065) (2025), Errors
- IRS: Draft 2026 Schedule K-1 (Form 1065) (draft, not for filing)
X1 Wealth provides planning and coordination tools. It does not prepare or file tax returns. This content is for informational purposes only and does not constitute legal, tax, or investment advice. Consult a qualified professional for advice specific to your situation.
