Guide · Tax
U.S. tax for international founders.
Formation creates a filing posture whether or not the company earns a dollar. This guide maps the recurring federal forms, the withholding documents counterparties request, and the state sales tax exposure that surprises founders later.
01 · The starting principle
Filing obligations exist without revenue.
The most common founder misconception is that a U.S. company with no U.S. revenue owes no U.S. filings. That is incorrect. A foreign-owned single-member LLC that is a disregarded entity still owes Form 5472 attached to a pro-forma Form 1120 every year it has reportable transactions — and reportable transactions include the capital contribution that funded the company.
Tax owed and filing owed are separate questions. Many international founders owe little or no U.S. income tax and still carry hard filing deadlines with real penalties. The operational posture is to treat the filing calendar as infrastructure, installed at formation.
02 · Form 5472
The foreign-owned LLC filing most founders miss.
Form 5472 reports transactions between a U.S. entity and its foreign owners or related parties. Since 2017, foreign-owned single-member LLCs — disregarded for income tax — are expressly required to file it, attached to a pro-forma Form 1120 that carries only the entity's name, address, and identifying details.
Reportable transactions are broad: capital contributions, distributions, loans between the founder and the company, and expenses paid on the company's behalf. The penalty for failure to file, late filing, or an incomplete form starts at $25,000 per year.
The deadline is 15 April for calendar-year entities, filed by fax or mail to a dedicated IRS unit — it cannot be e-filed as a standalone form. This is the single filing that separates well-operated foreign-owned LLCs from companies accumulating silent penalty exposure.
03 · Forms 1120 and 1120-F
Corporate returns, domestic and foreign.
A U.S. C-Corporation files Form 1120 annually, reporting worldwide income, regardless of whether the result is tax due, breakeven, or loss. The deadline is 15 April for calendar-year corporations, with extension available on Form 7004.
Form 1120-F is the return of a foreign corporation engaged in a U.S. trade or business. It becomes relevant in two scenarios international founders encounter: a foreign parent company operating directly in the U.S. without a subsidiary, and treaty-based positions where the foreign corporation claims it has no U.S. permanent establishment but wants protective filing to preserve deductions.
The structural takeaway: a U.S. subsidiary (Form 1120) and a foreign parent with U.S. activity (potentially Form 1120-F) are different postures with different exposure. Which structure the group takes is a decision to make deliberately with a cross-border tax advisor, not one to discover at filing time.
04 · The W-8 series
Withholding documents counterparties request.
The W-8 forms are not filed with the IRS — they are certificates given to U.S. withholding agents and counterparties to document foreign status and, where applicable, claim treaty-reduced withholding on U.S.-source income.
Form W-8BEN is for foreign individuals receiving U.S.-source income personally. Form W-8BEN-E is the entity equivalent, used by foreign companies — and it is the form a U.S. client's accounts payable team, a marketplace, or a payment platform will request from a foreign entity. Form W-8ECI applies when income is effectively connected with a U.S. trade or business; Form W-8IMY applies to intermediaries.
The operational reality: founders operating a U.S. LLC typically provide a W-9 from the U.S. entity and encounter W-8 forms at the group level — when a foreign parent, foreign founder personally, or foreign affiliate receives U.S.-source payments. Keeping executed, current W-8 forms on file is part of counterparty readiness; expired forms trigger default withholding at 30%.
05 · State sales tax
Nexus exists independent of income tax.
State sales tax is a separate regime from federal income tax, with its own triggers. Physical nexus — an office, employee, or inventory in a state — has always created collection obligations. Since the 2018 Wayfair decision, economic nexus does too: most states require registration and collection once sales into the state exceed a threshold, commonly $100,000 in annual sales.
For e-commerce founders, inventory in an Amazon FBA warehouse creates physical nexus in that state even with modest sales. For SaaS founders, states diverge: some tax SaaS, some exempt it, and the classification of the product determines the answer state by state.
Marketplace facilitator laws shift collection to the platform for marketplace sales — Amazon collects on FBA orders — but direct sales through the company's own checkout remain the company's obligation. The correct posture is a nexus review at launch and annually thereafter, not a retrofit after a state notice arrives.
06 · The recurring calendar
What actually repeats each year.
15 April: Form 5472 with pro-forma 1120 for foreign-owned single-member LLCs; Form 1120 for C-Corporations; extension requests on Form 7004. State returns follow their own schedules, generally aligned to the federal deadline.
State annual reports and franchise taxes run on separate state calendars — Delaware corporate franchise tax on 1 March, Delaware LLC tax on 1 June, and equivalents in every state of registration. Sales tax returns, where registered, run monthly or quarterly depending on volume.
The companies that stay in good standing are not the ones with the best accountants in April — they are the ones that installed the calendar in January. Our compliance roadmap guide maps the full recurring sequence in operational order.
07 · Honest boundaries
What this guide is — and is not.
This guide maps the filing and withholding landscape so founders can operate deliberately. It is not tax advice. Treaty positions, effectively-connected-income analysis, transfer pricing, and entity-level tax elections require a licensed cross-border tax advisor who has reviewed the actual facts.
Brightincorp coordinates the operational layer — entity maintenance, registered agent, filing-calendar discipline, and document readiness — and works alongside the founder's CPA or tax counsel. The division of labor is intentional: operations keep the company ready; advisors determine positions.
Frequently asked
Common questions.
My foreign-owned LLC earned no U.S. income. Do I still file anything?
Yes. A foreign-owned single-member LLC must file Form 5472 with a pro-forma Form 1120 every year it has reportable transactions — which include capital contributions and founder-funded expenses. The penalty for failure to file starts at $25,000.
What is the difference between Form 1120 and Form 1120-F?
Form 1120 is the annual return of a U.S. corporation, reporting worldwide income. Form 1120-F is the return of a foreign corporation engaged in a U.S. trade or business. A U.S. subsidiary files 1120; a foreign parent operating directly in the U.S. may file 1120-F.
When do I give a counterparty a W-8 instead of a W-9?
A U.S. entity provides a W-9. W-8 forms document foreign status — W-8BEN for foreign individuals, W-8BEN-E for foreign entities. If a foreign parent or affiliate receives U.S.-source payments, the payer will request the appropriate W-8. Expired or missing forms trigger 30% default withholding.
Do I owe state sales tax if I only sell online?
Possibly. Economic nexus rules in most states require registration and collection once sales into the state exceed a threshold, commonly $100,000 annually. Marketplace facilitator laws shift collection to platforms like Amazon for marketplace orders, but direct checkout sales remain the company's obligation.
Does a tax treaty eliminate these filings?
No. Treaties can reduce tax owed and withholding rates, but filing obligations generally remain — and some treaty positions are only protected by filing, such as a protective Form 1120-F. Treaty analysis is a licensed-advisor question.
Who prepares these filings?
Form 5472, corporate returns, and sales tax registrations are prepared by a CPA or tax preparer. Brightincorp coordinates the operational infrastructure — entity good standing, records, and filing-calendar discipline — so the preparer works from clean inputs.
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Operational coordination, engaged.
Brightincorp coordinates the operational sequence covered in this guide as part of every engagement — so the work is done, not merely described.