What Is a Schedule K-1 Tax Form? A Complete Guide for 2026

If you’re a partner in a business, a shareholder in an S corporation, or a beneficiary of a trust, chances are you’ve come across a Schedule K-1 at tax time — and wondered what to do with it.

A Schedule K-1 is an IRS tax form that reports an individual’s share of income, deductions, credits, and losses from a pass-through entity — such as a partnership, S corporation, trust, or estate. Unlike a corporation, these entities don’t pay federal income tax themselves. Instead, profits and losses “pass through” to the owners or beneficiaries, who report the amounts on their own personal tax returns.

Every partner, shareholder, or beneficiary receives their own Schedule K-1 each year, and a copy is also filed with the IRS. Getting the numbers on your K-1 right — and knowing exactly where they belong on your Form 1040 — can be confusing, which is why so many business owners and individual filers turn to a tax professional for help with outsourced tax services.

In this guide, we’ll break down exactly what a Schedule K-1 is, who has to file one, how K-1 income is taxed, and how to read every part of the form — line by line.

Quick Answer: Schedule K-1 in a Nutshell

• What it is: An IRS form used to report each owner’s or beneficiary’s share of a pass-through entity’s income, deductions, and credits.
• Who files it: Partnerships (Form 1065), S corporations (Form 1120-S), and trusts/estates (Form 1041).
• Who receives it: Partners, LLC members, S corp shareholders, and trust or estate beneficiaries.
• Where it goes: The information flows to the recipient’s Form 1040, primarily through Schedule E.
• Deadline: March 15 for partnerships and S corps (September 15 with an extension); April 15 for trusts and estates (September 30 with an extension).

What Is a K-1 Tax Form?

A K-1 tax form (formally, “Schedule K-1”) is the document a pass-through business entity uses to tell the IRS — and each individual owner — exactly how much of the entity’s income, loss, deduction, and credit belongs to them for the year.

Think of it this way: if a partnership earns $200,000 in taxable income and has two equal partners, the partnership itself doesn’t write a check to the IRS for that income. Instead, it issues a Schedule K-1 to each partner showing $100,000 of income. Each partner then reports that $100,000 on their own individual tax return and pays tax at their personal rate.

This “pass-through taxation” is what separates partnerships, S corporations, and most trusts from C corporations, which pay corporate income tax directly before any profits reach shareholders. If your business is still deciding on the right legal structure, our business formation services can help you weigh the tax implications of each entity type before you file.

Schedule K-1 vs. Schedule K: What’s the Difference?

This is one of the most common points of confusion. Schedule K and Schedule K-1 are related but not the same form:

In short, Schedule K is the whole pie; Schedule K-1 is each individual’s slice.

Types of Schedule K-1 Forms

Not all K-1s are identical. The specific version you receive depends on the type of entity that issued it.

1. Schedule K-1 (Form 1065) — Partnerships and Multi-Member LLCs

Partnerships, and LLCs taxed as partnerships, file Form 1065 as their business tax return and issue a Schedule K-1 (Form 1065) to each partner or LLC member. If your business is organized as a partnership or multi-member LLC, our LLC, LLP & partnership tax return services can handle both the entity-level Form 1065 filing and the K-1s issued to each partner.

2. Schedule K-1 (Form 1120-S) — S Corporations

S corporations file Form 1120-S and issue a Schedule K-1 (Form 1120-S) to each shareholder, based on their percentage of stock ownership. Because S corp K-1s don’t include self-employment tax the way partnership K-1s often do, the tax treatment can differ meaningfully. See our S corporation tax return services if your business has elected S corp status.

3. Schedule K-1 (Form 1041) — Trusts and Estates

Trusts and estates that distribute income to beneficiaries file Form 1041 and issue a Schedule K-1 (Form 1041) to each beneficiary. This is common in estate settlements and family trusts where income such as interest, dividends, or capital gains is passed through rather than taxed at the trust level. Learn more through our dedicated trust tax return services.

Who Is Required to File a Schedule K-1?

The responsibility for filing K-1s sits with the entity, not the recipient:

• Partnerships and multi-member LLCs must issue a Schedule K-1 to every partner or member, regardless of how small their ownership stake is.
• S corporations must issue a Schedule K-1 to every shareholder based on their ownership percentage.
• Trusts and estates must issue a Schedule K-1 to every beneficiary who received a distribution of income during the year.

If you’re the recipient of a K-1, you don’t file it separately with the IRS — the issuing entity already sends the IRS its own copy. You simply use the figures on your K-1 to complete your personal Form 1040. That said, if you receive a K-1, it’s worth having a professional review it as part of your individual tax return preparation, since a single missed box can trigger an IRS notice or a need to amend your return later.

Understanding the Parts of a Schedule K-1

Every Schedule K-1 — regardless of entity type — is organized into three main parts.

Part I: Information About the Entity

This section identifies the business or trust that issued the K-1, including its:

• Legal name and address
• Employer Identification Number (EIN)
• IRS filing location
• Entity type (partnership, S corp, or trust/estate)

Part II: Information About the Recipient (You)

This section is about the partner, shareholder, or beneficiary receiving the form. It typically includes:

• Your name, address, and Social Security Number or EIN
• Your ownership or profit-sharing percentage
• Your partner/shareholder type (general partner, limited partner, LLC member, etc.)
• Beginning and ending capital account balances (for partnerships)
• Whether you’re a passive or active participant in the business

Part III: Your Share of Current-Year Income, Deductions, and Credits

This is the part that actually affects your tax bill. It reports your specific share of items such as ordinary business income, rental income, interest, dividends, capital gains, deductions, and credits — each assigned to a specific numbered box with corresponding codes.

How Is K-1 Income Taxed?

K-1 income doesn’t get taxed at a single flat rate. Instead, each type of income or deduction on the form flows through to a different part of your personal tax return, and is taxed according to its own rules. Here’s how the most common items flow through to Form 1040:

A few important points to keep in mind:

• Profit increases your taxable income; a loss can decrease it — though loss deductions may be limited by your basis in the entity, at-risk rules, or passive activity limitations.
• Self-employment tax often applies to a general partner’s share of partnership income, but usually not to an S corp shareholder’s K-1 income (S corp shareholders who work in the business are instead paid W-2 wages, taxed separately).
• Don’t double-deduct. Ordinary operating expenses are already netted into the income figure reported in Box 1 — you shouldn’t deduct them again separately on your personal return.

Because K-1 income touches so many different schedules, this is an area where even experienced filers benefit from working with a firm that specializes in tax planning and advisory to avoid overpaying — or underpaying — based on how these items interact with the rest of your return.

Schedule K-1 vs. Form 1099 vs. Form W-2

People often assume a K-1 works like a 1099 or W-2, but the three forms report fundamentally different types of income.

It’s entirely possible to receive both a W-2 and a K-1 from the same company. For example, if you’re an S corp shareholder who also works in the business, you’d receive a W-2 for your salary and a Schedule K-1 for your share of the company’s remaining profit.

How to Read and Fill Out a Schedule K-1: Step-by-Step

If your business is responsible for issuing K-1s, here’s the general process:

1. Finalize the entity-level return first. Your Form 1065 or Form 1120-S must be substantially complete before K-1s can be accurately generated, since each K-1 is built from the entity’s total income and allocations.
2. Confirm ownership percentages and any changes during the year. Ownership shifts mid-year (a partner buying in or exiting) affect how income is allocated.
3. Allocate income, deductions, and credits to each partner or shareholder according to the partnership agreement, operating agreement, or stock ownership percentage.
4. Fill in Parts I, II, and III for each individual recipient, double-checking codes in Box 11 through Box 20, which vary significantly by entity type.
5. Distribute copies to each recipient no later than your tax filing deadline, and file the K-1s with the IRS as part of your complete return.
6. Keep basis schedules updated. Partners and shareholders need to track their basis year over year to know how much loss they can actually deduct — this isn’t always obvious from the K-1 alone.

If you’re the one receiving a K-1, your job is simpler but still requires care: transfer each reported item to the correct line of your Form 1040 using the K-1 instructions and codes as your guide, and hold onto the form (along with prior years’ K-1s) in case the IRS has questions about your basis or loss limitations later.

When Is Schedule K-1 Due?

K-1 deadlines follow the filing deadline of the issuing entity’s tax return:

• Partnerships (Form 1065) and S corporations (Form 1120-S): March 15, or September 15 with a valid extension.
• Trusts and estates (Form 1041): April 15, or September 30 with a valid extension.

Because these deadlines fall well before the typical April 15 individual filing deadline, it’s common to receive a K-1 late — or to know one is coming but not yet have the numbers. In that case, you may need to file Form 4868 for a personal extension rather than filing your Form 1040 with estimated (and potentially inaccurate) figures.

What Happens If a K-1 Isn’t Filed on Time?

The IRS penalizes late or missing K-1s on a per-form, per-month basis (indexed annually), applied separately for failing to file with the IRS and failing to furnish a copy to the recipient. Missing even one K-1 can also delay processing of the entity’s entire return or increase audit risk. Many states impose their own separate penalties on top of federal ones.

If your business has missed a K-1 filing, the fastest way to limit damage is to file the return (or an amended return) and issue the outstanding K-1s as soon as possible. In some cases, penalty relief may be available if you can show reasonable cause — a step where professional guidance from a virtual CFO or tax advisor can make a real difference in how the request is presented to the IRS.