A K-1 reports your share of income or loss from a partnership, S corporation, or trust

A K-1 form (officially Schedule K-1) tells you how much income, loss, deductions, or credits you owe taxes on from a business or investment you don't fully own. The business itself doesn't pay tax on all its earnings — instead, it passes that income through to you and other owners, and each of you pays tax on your share. The K-1 is how the business tells you what that share is.

You receive a K-1 if you own part of a partnership, an S corporation, a limited liability company (LLC) taxed as a partnership or S corp, or if you're a beneficiary of a trust or estate. The form arrives by January 31 each year and covers the previous calendar year. You use it to fill out your personal tax return.

The K-1 is not optional paperwork — if you received one, you must report the information on it to the IRS, even if the business had a loss instead of a profit. Failing to report it can trigger an audit or penalty.

Key Takeaways

  • A K-1 shows your personal share of business income, loss, deductions, or credits from a partnership, S corporation, LLC, or trust.
  • The business sends you the K-1 by January 31 and files a matching copy with the IRS, so your numbers must match.
  • You report K-1 income on your personal tax return even if the business lost money, because losses can reduce your other taxable income.
  • If you disagree with the K-1 amount, you must contact the business owner or manager first — the IRS will not change it without their sign-off.

Where the K-1 appears on your tax return

The K-1 information goes on Schedule E (Supplemental Income and Loss) if you own a partnership or S corporation, or on Schedule 1 (Additional Income) if you're a trust beneficiary. From there, the totals flow to your main Form 1040. The specific line depends on what type of income or loss the K-1 reports — ordinary business income, capital gains, charitable contributions, or tax credits all have separate boxes on the K-1 and separate lines on your return.

You cannot straightforward ignore a K-1 box because it's small or seems minor. The IRS receives a copy of every K-1 filed, and their computers match it to your Social Security number. If you don't report it, the IRS will notice the mismatch and may assess additional tax, interest, and penalties without giving you a chance to explain first.

The difference between K-1 income and W-2 wages

A K-1 is fundamentally different from a W-2. With a W-2, your employer withholds income tax, Social Security tax, and Medicare tax from each paycheck. With a K-1, no tax is withheld — you receive the full amount of your share and are responsible for paying tax on it yourself when you file your return.

This also means you may owe self-employment tax on K-1 income from a partnership or sole proprietorship. Self-employment tax covers Social Security and Medicare for people who are not traditional employees. The K-1 will tell you which portions are subject to self-employment tax and which are not. If you owe self-employment tax, you report it on Schedule SE and add it to your total tax bill.

An S corporation K-1 is different: S corp owners who are also employees receive a W-2 for wages they draw from the business, and a K-1 for their share of remaining profit. This split can lower self-employment tax compared to a partnership structure, which is one reason some business owners choose an S corp.

What happens if the K-1 amount seems wrong

If you believe the K-1 shows the wrong amount, contact the business owner, manager, or accountant who prepared it before you file your return. They may have made a calculation error, or you may have misunderstood how the business allocates income. Ask them to explain the number and, if they agree it's wrong, ask them to file an amended K-1 with the IRS.

Do not straightforward report a different number on your tax return. If you report a different amount than the K-1, the IRS will see the mismatch and will contact you — and they will assume the K-1 is correct unless you can prove otherwise. Amending the K-1 at the source is faster and cleaner than fighting with the IRS later.

If the business owner refuses to correct an error or won't explain the number, you have the right to file your return with the K-1 as issued and then file a separate dispute with the IRS. This is rare, but it can happen in situations where the business is poorly managed or the owner is uncooperative. In that case, keep copies of all your communications with the business owner so you have a record if the IRS asks questions.

K-1 losses and how they affect your taxes

A K-1 can report a loss instead of income. If the business or trust lost money, your share of that loss flows to your tax return and reduces your taxable income from other sources — your job, investments, or other businesses. This can lower your total tax bill or even create a refund.

However, there are limits. Passive activity loss rules prevent you from using losses from a business you don't actively manage to offset wages from your job. If you're a silent partner in a partnership or a minority shareholder in an S corporation, your losses may be limited to the amount you have "at risk" — the money you actually invested plus any loans you personally may provide. Losses beyond that amount carry forward to future years.

If you actively manage the business, you may be able to use the full loss. The IRS defines "active" narrowly, so read the instructions carefully or ask a tax professional if you're unsure whether your losses are limited.

Amended K-1s and late arrivals

Sometimes a business files an amended K-1 after the original important date. This happens when the business discovers an error, gets audited by the IRS, or realizes it made a mistake in calculating allocations. An amended K-1 is labeled as such and will have a different amount than the original.

If you already filed your return with the original K-1, you will need to file an amended return (Form 1040-X) to report the corrected amount. The business should notify you when they file an amended K-1, but it's your responsibility to track it and amend your return if necessary. If you don't amend and the IRS catches the discrepancy, you may owe additional tax plus interest.

If a K-1 arrives after you've already filed, check the date on the form. If it's for a year you've already reported, file an amended return. If it's for the current year and you haven't filed yet, wait for the corrected version before you file.

When you receive a K-1 for a business you no longer own

If you sold your stake in a partnership or S corporation partway through the year, you should receive a K-1 that covers only the portion of the year you owned it. The new owner receives a separate K-1 for their portion. Make sure the dates on the K-1 match when you actually owned the business.

If you receive a K-1 for a year after you sold your interest, contact the business when ready. This is usually a clerical error — the business may not have updated its records to show you as a former owner. Ask them to issue a corrected K-1 with zero income, or to confirm in writing that you should not have received one. Keep that confirmation in case the IRS questions why you didn't report it.

Frequently Asked Questions

Do I have to report a K-1 if the amount is very small?

Yes. The IRS receives a copy of every K-1 filed and matches it to your Social Security number by computer. Even a K-1 for $1 must be reported on your tax return. Failing to report it can trigger an audit or penalty.

What if I lost the K-1 and can't find it?

Contact the business owner or their accountant and ask for a copy. They are required to send you one by January 31. If you file your return without it and the IRS sees the mismatch, you'll have to file an amended return. It's faster to get the copy first.

Can I file my return before I receive the K-1?

You can file using Form 4868 to request an automatic extension, which gives you until October 15 to file. However, you cannot file your actual return without the K-1 — you need the information to complete Schedule E or Schedule 1. Filing an extension buys you time to wait for it.

Does a K-1 from a trust work the same way as one from a partnership?

Mostly, but trust K-1s report different types of income and have different rules about deductions. Trust income can include capital gains, dividends, and charitable contributions that flow through to you. The instructions on the K-1 will specify which schedule to use. If you're unsure, a tax professional can walk you through it.

What if the K-1 shows income but I didn't receive any money?

The business may have retained earnings instead of distributing them to owners. You still owe tax on your share of the income, even if you didn't receive cash. This is common in growing businesses that reinvest profits. Ask the business owner for an explanation if you're surprised by the amount.