Multi-Member US LLC Taxes for Non-US Founders in 2026

A single-member LLC owned by a non-resident is a disregarded entity by default. The owner files Form 5472 alongside a pro-forma Form 1120 to report cross-border transactions. No profits pass through to a US partnership tax return, and compliance remains relatively cheap.

The moment a second person joins the LLC, the IRS treats the business as a partnership. It does not matter whether the second member owns 50 percent or 1 percent. Even husband-and-wife businesses owned by non-residents are partnerships unless formed in specific community property states, which rarely applies to foreign founders.

This shift removes you from Form 5472 territory and drops you into Subchapter K of the Internal Revenue Code. Your compliance costs will increase substantially because preparing a partnership return requires formal balance sheets and capital account maintenance.

A multi-member LLC must file Form 1065 (U.S. Return of Partnership Income) every year. The partnership itself does not pay federal income tax. Instead, it reports income, deductions, gains, and losses, which flow through to the individual owners.

Alongside Form 1065, the business generates a Schedule K-1 for every partner. The Schedule K-1 details each owner's distributive share of the LLC profits and losses. Even if you do not withdraw money from the business bank account, you are taxed on your allocated share of the profits.

The deadline for Form 1065 is March 15 for calendar-year entities, one month earlier than individual income tax returns. You can request an automatic six-month extension by filing Form 7004 before March 15, which moves your final filing deadline to September 15.

If your multi-member LLC generates Effectively Connected Income (ECI), Section 1446 of the Internal Revenue Code requires the LLC to withhold tax on foreign partners. ECI typically exists if you have physical operations, dependent agents, or employees working on the ground in the United States.

The LLC must withhold tax on each foreign partner's allocable share of effectively connected taxable income at the highest marginal rate. For non-resident individuals, this withholding rate is 37 percent. For foreign corporate partners, the rate is 21 percent.

This withholding is not optional. The LLC acts as the withholding agent and is directly liable for the tax if it fails to collect and remit the funds. Failing to pay Section 1446 withholding can lead to personal liability for the managing partner.

When Section 1446 withholding applies, the LLC cannot simply pay the tax at the end of the year. The business must make quarterly installment payments to the IRS using Form 8813 (Partnership Withholding Tax Payment Voucher).

At year-end, the LLC files Form 8804 (Annual Return for Partnership Withholding Tax) to reconcile all payments made throughout the year. Each non-US partner also receives Form 8805, which shows their total income subject to withholding and the exact tax paid on their behalf.

Foreign partners must then file a personal US non-resident tax return (Form 1040-NR) to claim credit for the taxes withheld. If the 37 percent flat withholding exceeded their actual graduated tax liability, the IRS issues a refund for the difference.

Many digital businesses, software startups, and remote consulting agencies run by non-US founders do not generate ECI. If all founders and contractors work outside the US and the LLC has no domestic physical footprint, your income is generally foreign-source income.

In this scenario, Section 1446 withholding does not apply because there is no effectively connected taxable income. The LLC reports zero US-source taxable income on Form 1065, and Schedule K-1 shows foreign-source income distributions.

Even with zero US tax owed, the LLC must still file Form 1065 and issue K-1s. The filing requirement is based on operating an active US partnership, not on whether you owe money to the US Treasury.

Every member listed on Form 1065 must have a US tax identification number. For non-residents who do not qualify for a Social Security Number, this means obtaining an Individual Taxpayer Identification Number (ITIN).

The IRS requires an ITIN to process Schedule K-1 and tie partnership allocations to an identifiable individual. If you file Form 1065 with foreign partners lacking ITINs, the IRS will accept the return but issue error notices and may delay processing or disallow certain partner deductions.

You can apply for an ITIN by filing Form W-7 alongside a certified copy of your passport through an IRS Certified Acceptance Agent. If you form your company through Bastion Formations, the team can coordinate your state filing, EIN, and partner ITIN applications simultaneously to keep your tax profiles clean from day one.

Failing to file Form 1065 on time results in severe penalties under IRC Section 6698. In 2026, the late filing penalty is $245 per partner per month, up to a maximum of 12 months. An LLC with two partners that ignores its return for one year faces an automatic penalty of $5,880.

Accounting fees for a multi-member LLC are higher than those for a single-member entity. While a simple single-member Form 5472 package typically costs $500 to $1,000 from an international CPA, a proper Form 1065 with Schedules K-1 usually runs between $1,500 and $3,500 annually.

If you do not truly need a partnership, keeping a US LLC as a single-member entity or having co-founders operate separate single-member entities that invoice each other can simplify your US tax footprint. Choose your structure based on real investor requirements rather than casual co-founder agreements.