US LLC Tax for Non-Residents: Do You Actually Owe US Tax?

• A nonresident is generally taxed by the U.S. only on U.S.-source income or income effectively connected to a U.S. trade or business (ECI/ETBUS). HIGH, IRS
• Under IRS guidance, a foreign person is generally engaged in a U.S. trade or business when personal services are performed in the U.S. and the activity is "considerable, continuous, and regular." Selling services or SaaS to U.S. customers from abroad, with no U.S. office, employees, or dependent agent, generally does not meet that bar, but it's fact-specific. (General; confirm with a CPA.)
• "No U.S. tax" does not mean "no filing": Form 5472 + pro-forma 1120 generally apply regardless. HIGH
• A tax treaty with your country may affect the analysis; many countries have one, some don't (e.g. no US treaty with Nigeria, Colombia, Argentina, UAE). HIGH for existence; application REVIEW
• Your home country may tax the same income, treaty relief or foreign tax credits may help. NEEDS LOCAL EXPERT REVIEW

The U.S. taxes a nonresident's business income when that income is "effectively connected" to a U.S. trade or business, which usually requires real U.S. presence: an office, employees, or a "dependent agent" acting for you in the U.S. A founder abroad serving U.S. clients online typically doesn't have that. But warehouses, U.S.-based staff, or exclusive U.S. agents can change the answer. Note for ecommerce: selling inventory where title passes in the U.S. (for example, goods shipped from a U.S. warehouse or via FBA) is more likely to be ECI. Get this checked. This is exactly the kind of line that depends on your facts. Confirm it.

Don't assume "U.S. LLC = no tax," and don't assume "no tax = nothing to do." Budget for the annual Form 5472 filing regardless, and get a U.S. CPA to confirm whether your activities create ECI. Then check your home country's treatment, that's often where the real tax lives.

The biggest myth is "a U.S. LLC for a non-resident never pays U.S. tax." It's often true in practice for service businesses run from abroad, but it's not a rule, it's a fact-dependent outcome, and stating it as a guarantee is how founders get blindsided. The second myth is forgetting the filing obligation entirely.

ECI: effectively connected income. ETBUS, engaged in a trade or business in the U.S. Dependent agent, someone acting for you in the U.S. who can create ECI. Form 5472 / 1120. The annual filing. Tax treaty. A bilateral agreement that can reduce double taxation.