Multi-member LLC tax for non-residents: Form 1065, K-1s, and other differences to single-member LLCs

If you co-founded a US LLC with someone else, you have a multi-member LLC, and your tax situation is fundamentally different from everything you’ve read about single-member LLCs. The IRS automatically classifies your multi-member LLC as a partnership. That one change triggers a different set of tax forms, a different filing deadline, and compliance obligations that tax guides for single-member LLCs don’t address.

The filing deadline for the 2025 tax year was March 16, 2026. If your LLC hasn’t filed yet and you didn’t request an extension by that date, you’re in late-filing territory. You should act as soon as possible to avoid penalties piling up. If you filed a timely extension, you have until September 15, 2026. 

This multi-member LLC tax guide walks you through exactly what’s required, and what to do if you’re behind.

Not sure where your LLC stands? Book a tax consultation with our team.

How the IRS classifies your LLC once you have a co-founder

The moment your LLC has two or more members, the IRS classifies it as a partnership for federal tax purposes. This is not an election; it happens automatically under the default entity classification rules. It doesn’t change your LLC legally or operationally, it only changes how the IRS expects it to report.

What that means in practice: the LLC files its own annual information return (Form 1065), issues a separate tax document to each member (K-1), and operates under partnership tax rules. The single-member setup, where the LLC files Form 5472, no longer applies.

Your LLC can opt out of this default by filing Form 8832 to elect C corporation treatment. (S corporation status is not available to a LLC with a foreign member.) While the partnership default is far more common, a C corp can have benefits in certain business models, like e-commerce. 

The guide focuses on the default taxation of multi-member LLCs as partnerships.

What “taxed as a partnership” actually means

Form 1065: Partnership information return

The IRS requires every multi-member LLC taxed as a partnership to file Form 1065, U.S. Return of Partnership Income, each year. This is an information return, meaning the LLC reports its income, deductions, and credits, but pays no entity-level federal income tax on them.

The IRS requires Form 1065 even if the partnership had no income during the year, as long as it had any deductible expenses. In practice, almost every operating LLC clears that bar: state registration fees, bank fees, software subscriptions, and professional services all count. A truly dormant LLC with zero income and zero expenses is the narrow exception.

Schedule K-1: For each partner’s share

Once the LLC’s tax preparer completes Form 1065, they also prepare a Schedule K-1 for every member. The K-1 is not a separate document you produce independently, but it’s generated as part of the tax return preparation. Entity Inc. issues K-1s to each member as part of our partnership tax preparation service, typically by the filing deadline so members have what they need for their own personal returns.

Each K-1 shows the member’s allocated share of the LLC’s income, losses, deductions, and credits for the year, based on the ownership percentages (or any special allocations) set out in your operating agreement. Members use their K-1 to complete their own personal tax returns.

For US members, K-1 income is taxable in the year it is allocated, whether or not the money was actually distributed. If your LLC earned $100,000 and you own 50%, you have $50,000 of allocated income on your K-1, even if the cash stayed in the LLC’s bank account.

For foreign (non-resident) members, the taxability of that allocated income depends on its character. The IRS taxes non-resident partners on their share of ECI — income effectively connected to a US trade or business. Income that is not ECI, including most foreign-source income, is generally not subject to US tax. The K-1 reflects the allocation regardless, but what you actually owe in the US flows from how the income is classified. We briefly cover ECI below; also check out our in-depth guide to ECI (Effectively Connected Income).

Schedule K-1 (Form 1065): The tax document the partnership issues to each member, showing their allocated share of the LLC’s income, deductions, and credits for the year. The LLC’s tax preparer generates K-1s as part of the Form 1065 preparation. Non-resident members use their K-1 to determine any US individual tax return obligations.

Schedules K-2 and K-3

Partnerships with international tax relevance, which includes virtually any LLC with non-resident members, must also file Schedules K-2 and K-3. Schedule K-2 is an extension of Schedule K that captures items of international tax relevance at the partnership level. Schedule K-3 is the partner-level version, issued to each member alongside their K-1.

These schedules are frequently missed, especially by US-based accountants who primarily handle domestic returns. If your LLC has foreign members and your tax preparer hasn’t mentioned K-2 and K-3, it’s worth asking.

Do multi-member LLCs file Form 5472?

Multi-member LLCs taxed as partnerships do not file Form 5472.

This is one of the most common points of confusion for foreign founders and even for accountants who primarily work in the single-member LLC space. Form 5472 applies to US corporations with 25% or more foreign ownership, and to foreign-owned single-member LLCs that are treated as disregarded entities. It does not apply to partnerships.

A multi-member LLC taxed as a partnership is a different reporting entity in the eyes of the IRS. It files Form 1065 and issues K-1s. The partnership tax system is how the IRS gets visibility into the entity’s activity and each partner’s allocated income. Form 5472 is a separate regime for a different structure entirely.

The one scenario where Form 5472 does come into play: if your multi-member LLC elected to be taxed as a C corporation by filing Form 8832, and at least one foreign member owns 25% or more, the LLC would then file Form 5472 attached to a full Form 1120. Because of the elected tax treatment, corporate rules apply, not the partnership rules.

I see this mistake regularly: founders who formed a multi-member LLC but were told to file Form 5472 because their advisor was applying single-member LLC rules. Filing 5472 for a partnership is the wrong form. If that’s happened to you, the right move is to understand whether you also missed the Form 1065 requirement and address both. An amended or late return is a much better position than compounding the error.

— Vincenzo Villamena, CPA — CEO at Entity Inc.

Withholding on foreign partners’ share of ECI

If your LLC generates income that is effectively connected to a US trade or business (ECI), the partnership must withhold US tax on each foreign partner’s allocated share of that ECI, and remit it to the IRS quarterly.

This obligation belongs to the partnership, not to the individual foreign partners. The mechanics work through various forms: 

• Form 8804 Annual Return for Partnership Withholding Tax
• Form 8804-C to reduce or eliminate the withholding if there’s a tax treaty with the US
• Form 8805 Foreign Partner’s Information Statement of Section 1446 Withholding Tax.
• Form 8813 to pay the withholding tax 

Form 8805 is issued to each foreign partner and functions similarly to a W-2 or 1099. It shows how much tax was withheld on their behalf.

Many multi-member LLCs with foreign partners miss this entirely. They have this  withholding obligation even if they didn’t distribute profits. Missing it means that the IRS can charge interest on top of the unpaid withholding.

What counts as ECI – Effectively Connected Income?

ECI is income arising from a trade or business conducted within the United States. Services performed while physically being in the US, sales of US-held inventory to US customers, US-based operations: these can generate ECI. 

Income sourced entirely outside the US, like services performed from abroad or operations run from outside the country, generally does not generate ECI for non-resident partners. Determining what is and what isn’t ECI can be complex and nuanced, especially for e-commerce. If you’re unsure about your situation, talk to our tax experts.

Many of the international founders we work with have a US LLC as legal entity, but the actual business operations are outside the US. In that case, the partnership still files Form 1065 and issues K-1s, but the ECI withholding requirement may not apply. The determination depends on the specific facts of how the business operates.

Do foreign partners need to file an individual tax return in the US?

The answer depends on whether the LLC generates ECI. (As you can see, ECI is a key concept for taxation of foreign-owned US businesses.)

Business and individual tax returns often get confused by non-residents. A personal or individual US tax return refers to the individual-level filing you make as a person, separate from what the LLC itself files as a business entity. 

As discussed earlier, a multi-member LLC files IRS Form 1065, regardless of where the members live. If there’s no ECI, and any US-source income (like interest or dividends) was properly withheld at source, then the non-resident partner may not have a US personal filing requirement.

But if the partnership has ECI and withholds tax on the foreign partner’s share, that partner will generally need to file Form 1040-NR to report that income and reconcile any withholding. 

Even without a personal US tax obligation, foreign partners almost always must disclose their LLC income in their home country or country of tax residence. Most tax systems require disclosure of foreign income, even when you don’t have to pay US tax. Consult with an advisor familiar with your home country’s rules.

Having both US and non-US co-founders

When a partnership has both US-resident and non-resident members, both receive K-1s from the same Form 1065. But the IRS does not treat them the same.

The US member reports their K-1 income on a standard Form 1040. The non-resident member’s treatment depends on whether there is ECI. The partnership’s withholding obligation under Section 1446 is only on the foreign partner’s share of ECI, not on the US partner’s share, and not on any non-ECI income.

Many foreign founders assume that having a US-based co-founder simplifies the non-resident partner’s compliance. It doesn’t. The partnership still has to run the ECI analysis, withhold if applicable, and issue Form 8805 to the foreign partner. And the US partner’s presence doesn’t change the foreign partner’s home-country reporting obligations. These are separate questions that need to be answered separately.

Filing due dates and penalties

For calendar-year partnerships, the IRS required Form 1065 for the 2025 tax year to be filed by March 16, 2026. (March 15 was a Sunday, so the deadline shifted to the following Monday.)

A six-month extension to September 15, 2026 was available by filing Form 7004, but the extension request had to be submitted by March 16. If your LLC missed that window without filing, the return is now late and penalties are accruing.

The IRS charges a late-filing penalty of $255 per partner per month (or partial month), for up to 12 months, even when the LLC owes no tax. For a two-member LLC that files three months late without a valid extension, that could mean $1,530 in penalties on a zero-income return.

That said, penalties are often reduced or eliminated. The IRS considers reasonable cause arguments. First-time filers have access to the First Time Abatement program, which frequently results in full penalty relief for partnerships with a clean compliance history. At Entity Inc., we have extensive experience filing late returns and pursuing penalty abatement. It’s a much better outcome than leaving the situation unresolved.

If you filed a valid extension: you have until September 15, 2026 to file the complete Form 1065 with all K-1s, Schedules K-2 and K-3, and any applicable Forms 8804 and 8805.

I’ve seen founders put off the late Form 1065 because they assume the penalty for a zero-income LLC can’t be that serious. The per-partner, per-month structure makes it add up fast. File the return, even late, and deal with the penalty situation directly. Abatement is available, but only if you take action.

— Vincenzo Villamena, CPA — CEO at Entity Inc.

What if you filed Form 5472 instead of Form 1065?

This is a common error, and it’s fixable. But it needs to be addressed directly rather than ignored.

Filing Form 5472 for a multi-member LLC taxed as a partnership does not satisfy the partnership’s filing requirement. The IRS treats these as two entirely separate regimes. Filing the wrong form means Form 1065 was never filed, and the late-filing clock has been running since March 16, 2026.

Here’s what needs to happen:

1. File Form 1065 (and all required K-1s, Schedules K-2 and K-3, and Forms 8804/8805 where applicable) as soon as possible. Even if it’s late, filing stops the penalty clock.
2. Assess whether the Form 5472 filing itself created any issues. In most cases it won’t generate adverse consequences on its own, but it’s worth reviewing to make sure nothing was reported incorrectly.
3. Pursue penalty abatement if penalties have accrued. First-time abatement is available and frequently granted for partnerships that have no prior compliance issues. A reasonable cause statement can also support relief in appropriate circumstances.

This comes up regularly in our practice: founders who were advised by an LLC formation service who applied single-member LLC rules to a partnership structure. The fix isn’t complicated, but it does require actually filing the right return. The longer you wait, the larger the penalty exposure. If this is your situation, the time to act is now.

— Vincenzo Villamena, CPA — CEO at Entity Inc.

Why clean books matter more in a partnership

Partnership returns are more complex than single-member LLC returns, and the accuracy of Form 1065 depends directly on the quality of your financial records.

K-1 allocations flow from the partnership’s financials. If income is misclassified, expenses are uncategorized, or capital account balances are unreconciled, the K-1s will be wrong. This can affect every member’s personal return. Amended returns for a multi-member LLC are expensive and time-consuming, partly because every K-1 recipient needs an amended form.

Clean, reconciled books also matter for ECI determinations. The analysis of whether income is effectively connected depends on transaction-level records: where services were performed, how revenue is sourced. Without clean books, that analysis becomes a guessing exercise.

At Entity Inc., our bookkeeping service is built around the compliance requirements of international LLC structures — not just clean P&Ls, but the documentation that supports accurate partnership allocations and defensible ECI positions. Learn more about our bookkeeping service.

FAQ

Does a multi-member LLC need to file Form 5472?

What tax forms does a multi-member LLC with foreign partners need to file?

What is the deadline for filing Form 1065 for a 2025 return?

What happens if a multi-member LLC misses the Form 1065 deadline?

Does a non-resident partner in a US LLC need to file a US tax return?

What if I filed Form 5472 for my multi-member LLC instead of Form 1065?

Do all-foreign multi-member LLCs owe US tax?

Take the next step

If your multi-member LLC hasn’t filed its 2024 partnership return yet, or if you’re not sure whether your current filing situation is correct, we can help you sort it out and get compliant.

Book a tax consultation with our experts.