Forming a US LLC from the UK: Complete Guide (2026)

UK residents form US LLCs for three reasons: US market access, Stripe simplicity, and the appeal of a $0 state income tax entity in Wyoming or Delaware. The formation part is easy. The tax picture is not.

Since April 2025, HMRC classifies US single-member LLCs as "opaque" — corporation-like for UK tax purposes — even though the IRS treats them as transparent. This mismatch creates a structural tax trap that most formation guides skip entirely, because formation services have no incentive to explain what happens after the sale.

I have run cross-border entities between the US, China, Hong Kong, and other jurisdictions for close to twenty years. The UK-US LLC mismatch is not new. HMRC has always been uneasy about how to classify LLCs. But the formal shift to "opaque" treatment in 2025 turned a gray area into a real compliance obligation. Below: five mechanical steps to form and operate a US LLC from the UK, followed by the HMRC classification issue that makes this structure harder for UK residents than for founders almost anywhere else.

Step 1: Choose a State

Three states dominate for non-resident LLC formation. For all five commonly discussed states, see the full state comparison.

For most UK solo founders, Wyoming is the practical default. $100 to form, $60/year to maintain, explicit single-member charging order protection, no state income tax. Doola, Firstbase, and Northwest all offer Wyoming formation.

Delaware makes sense if you are raising venture capital from US investors. The Court of Chancery and Delaware corporate case law are what institutional investors and their attorneys expect. For a UK freelancer billing through Stripe or a bootstrapped SaaS founder, that legal infrastructure adds ~$240/year in state fees for no practical benefit.

Delaware vs Wyoming for non-residents covers the full comparison.

Step 2: Form the LLC

You need three things:

1. Registered agent — A US-based person or company that receives legal and tax documents for the LLC. Required in every state. $50 to $300/year. This address goes on your public state filing.

2. Articles of Organization — Filed with the secretary of state. LLC name, registered agent, basic structure. Most states process in 1-5 business days; expedited (24-48 hours) costs extra.

3. Operating Agreement — Not filed with the state, but important. Defines ownership, management, and profit distribution. Even single-member LLCs need one. It establishes the separation between personal and business assets, and US banks will ask for it when you open an account.

No US state restricts LLC formation based on citizenship or residency. A UK passport works as primary ID throughout.

Formation services handle all three steps. $297 to $500 for the initial package, $199 to $399/year for renewals. Full cost breakdown.

Step 3: Get an EIN from the UK

An Employer Identification Number (EIN) is the LLC's federal tax ID. You need it for bank accounts, tax returns, and payment processors. UK residents can get one without an SSN or ITIN.

Three methods, ranked by speed:

Key fields on Form SS-4 for UK residents:

• Line 7b (SSN/ITIN of responsible party): Enter "FOREIGN"
• Line 4a-b (Mailing address): A UK address works fine
• Line 16: Check the box for responsible party address outside the US

The phone method is fastest. Calling at 11:00 AM GMT reaches the IRS at 6:00 AM Eastern, when hold times are shortest. Full process: How to Get an EIN Without an SSN.

Step 4: Open a US Bank Account

UK founders have it easier here than founders from most other countries. No OFAC issues, UK passports are universally accepted for identity verification, and UK addresses carry no extra compliance flags with US fintechs. For a detailed walkthrough of the account opening process, see the UK national's guide to opening a US bank account.

For UK founders specifically, Wise Business has one clear edge: GBP alongside USD in the same account. If you bill US clients in USD and pay UK expenses in GBP, you can manage both without external transfers. Mercury has stronger US banking features (treasury, credit cards, integrations) but is USD-only, so you will need a separate transfer to move funds back to a UK account.

Mercury, Wise, and Relay compared for fees, features, and non-resident account opening.

The HMRC Trap: Why UK Residents Face a Unique Problem

Everything above works identically for UK founders as for founders from any other country. State selection, formation, EIN, banking. Mechanical steps. They work.

Here is where the UK-specific risk lives.

The Classification Mismatch

The US and the UK treat a single-member LLC differently for tax purposes:

This mismatch was a gray area for years. HMRC's International Manual (INTM180030) has long said that UK tax treatment of a US LLC depends on whether it is classified as "transparent" or "opaque" under UK domestic law, not US law. Since April 2025, the position is explicit: a US single-member LLC is opaque for UK purposes.

Why This Creates Double Taxation Risk

The problem is mechanical. Say a UK resident operates a US single-member LLC earning $100,000 from US clients:

US side (IRS): The LLC is disregarded. The $100,000 passes through to the UK owner. If the income is not effectively connected with a US trade or business (ECI), no US income tax is due. If it is ECI (say the founder performs services while physically in the US), US tax applies.

UK side (HMRC): HMRC sees the LLC as a separate opaque entity. It does not "look through" to the individual. The LLC's profits are not automatically attributed to the UK owner's personal income. Instead, HMRC may:

1. Tax distributions as dividend income when profits reach the UK owner, even though the IRS treats the same distribution as a non-event (the LLC is disregarded, so there is no "distribution" in US tax terms)
2. Apply the Transfer of Assets Abroad (TOAA) rules under Income Tax Act 2007, Sections 714-751, attributing the LLC's income to the UK owner if the LLC qualifies as a "person abroad" to whom income has been transferred
3. Apply Controlled Foreign Company (CFC) rules in limited cases, though these primarily target UK companies, not individuals

The Treaty Does Not Fully Resolve This

The US-UK Double Taxation Convention (2001) has Article 24 (Non-Discrimination) and the Exchange of Notes on LLCs. The treaty acknowledges that the US treats LLCs as transparent. But:

• Article 1(8) says income through a fiscally transparent entity is treated as income of a resident of a Contracting State, but only "to the extent that" the income is treated as the resident's income under that state's domestic law.
• Since HMRC treats the LLC as opaque, it does not treat the LLC's income as the UK resident's income. This breaks the mechanism that would otherwise provide treaty relief.
• The result: The UK owner may not be able to claim Foreign Tax Credit Relief (FTCR) for US taxes paid, because HMRC does not recognize the income as belonging to the individual. And if HMRC taxes distributions as dividends, the US does not recognize a dividend event (because the LLC is disregarded), so there is no US tax to offset.

Each country's classification prevents the other country's tax relief from activating. That circularity is the core of the HMRC trap.

What This Means in Practice

• No US tax due (non-ECI income): HMRC may still tax distributions or attribute income under TOAA rules. No double taxation, but the UK tax treatment may be worse than if the income came through a UK structure, because dividend treatment and TOAA attribution carry different rates than trading income.

• US tax applies (ECI): Both countries may tax the same income. The US taxes it as pass-through; the UK taxes it as dividends or under TOAA. Foreign tax credit relief may be unavailable because HMRC does not match the income to the same category the IRS uses.

• LLC retains profits (no distribution): Under TOAA rules, HMRC may attribute retained income to the UK owner regardless of distribution. The UK taxable event is income arising in the entity abroad, not the distribution itself.

Self-Assessment Obligations

The HMRC tax reporting guide for UK residents with US LLCs covers the full compliance picture, including Self-Assessment specifics, NIC treatment, and FTCR mechanics.

UK residents are taxed on worldwide income. If you operate a US LLC, you report that income through Self-Assessment (SA100) regardless of whether you actually move the money to the UK.

What to Report

Foreign Tax Credit Relief (FTCR)

If US tax has been paid on the LLC's income (ECI or US withholding), you may claim Foreign Tax Credit Relief to offset the UK liability. Claimed on form SA106.

The catch: FTCR only works when both countries tax the same income and HMRC recognizes it as yours. If HMRC re-characterizes the income as dividends rather than trading profits, the credit may not align with what the US taxed on a different characterization of the same economic income.

HMRC's guidance on FTCR (HS263) covers the mechanics. For LLC-specific treatment, INTM180030 addresses entity classification.

Filing Deadlines

Both countries require annual filings. The US filing (Form 5472) is required even with zero revenue. The $25,000 penalty per missed form is the largest compliance risk on the US side. What happens if you miss Form 5472.

National Insurance Implications

UK residents earning trading income through a US LLC may owe National Insurance Contributions (NIC). Again, the answer depends on how HMRC classifies the income.

Class 2 and Class 4 NIC

If HMRC classifies the income as self-employment trading income (more likely when you are actively performing services through the LLC), Class 2 and Class 4 NIC apply on the profits.

If HMRC classifies it as investment/dividend income from an opaque entity, NIC does not apply. NIC is charged on earned income from a trade, not on investment income.

A UK founder earning $80,000 through a US LLC faces a very different NIC bill depending on which classification HMRC lands on. The irony: the opaque classification that creates double taxation risk also removes NIC liability. The transparent classification that would simplify income tax triggers NIC instead.

The US-UK Social Security Totalization Agreement

The US-UK Totalization Agreement prevents double social security contributions. A self-employed UK resident pays NIC in the UK, not US self-employment tax (Social Security + Medicare).

But this only applies if the individual is self-employed. If HMRC classifies the LLC income as investment income, the Totalization Agreement is irrelevant.

UK Ltd vs US LLC: When Each Structure Makes Sense

For UK residents, this choice is not about formation. It is about where the structural weight of the business sits.

When a UK Ltd is simpler

• Clients are primarily in the UK or Europe
• Revenue is in GBP or EUR
• You want one jurisdiction to worry about
• The business is services-based with no need for US banking or US market positioning
• IR35 considerations drive the corporate structure (UK Ltd is the standard vehicle)

When a US LLC adds value

• Clients are primarily in the US and pay in USD
• US market credibility matters (B2B SaaS, enterprise procurement, US partnership agreements that favor US-domiciled entities)
• You need US banking infrastructure (ACH, domestic wires, US checking account)
• You are building a product business with US-based revenue that will grow beyond services

When you need both

Some UK founders run both: a UK Ltd for UK/EU clients and a US LLC for US clients. More compliance (two sets of filings, intercompany transfer pricing), but it cleanly separates jurisdictional exposure. Each entity bills clients in its own jurisdiction, and the HMRC classification issue becomes narrower because the US LLC's income is clearly US-sourced.

FAQ

Can a UK resident legally form a US LLC?

Yes. No US state restricts LLC formation based on nationality or residency. A UK passport and UK address are sufficient. No visa, no SSN, no US visit required.

How does HMRC classify a US single-member LLC?

As opaque: corporation-like for UK tax purposes. Based on UK domestic law, not US tax law. The IRS treats the same entity as disregarded (transparent). That mismatch is the source of all the tax complexity above. See HMRC International Manual INTM180030.

Do UK founders pay US income tax on the LLC's earnings?

A single-member LLC owned by a non-US person with no US permanent establishment and no effectively connected income (ECI) generally owes no US income tax on business profits. The LLC is disregarded, and under the US-UK treaty, business profits are taxable only in the country of residence (the UK) unless attributable to a US permanent establishment. If the income is ECI (e.g., the founder performs services while physically in the US), US tax applies.

What is the total annual compliance cost?

That is the ongoing cost after formation. Year 1 adds $297-$500 for the formation service. A UK Ltd, by comparison, runs roughly $500-$1,500/year.

Can I avoid the HMRC classification issue by electing C-Corp status?

You can. File IRS Form 8832 to elect corporate treatment. Both countries would then agree on the classification (HMRC already treats the LLC as opaque). The trade-off: the LLC owes US corporate income tax (21% federal), plus a second layer when profits are distributed. Whether that produces a better outcome than the current mismatch depends on income levels, profit retention plans, and treaty credit calculations. This is one where you need a cross-border tax adviser who knows both systems.

Key Takeaways

• Formation mechanics are identical to any other non-resident: state filing, EIN by phone or fax, remote bank account, operational within 2-8 weeks
• Wyoming at $100 + $60/year is the practical default unless you are raising US venture capital
• UK founders have easier US banking access than most countries. Mercury, Wise Business, and Relay all accept UK applicants without friction
• HMRC has classified US single-member LLCs as opaque since April 2025, creating a mismatch with the IRS that may result in incomplete treaty relief
• The US-UK treaty does not fix the mismatch because HMRC does not recognize LLC income as the individual's income under UK domestic law
• LLC income goes on SA106 (Foreign) in Self-Assessment, classified as either trading or investment income depending on HMRC's view
• NIC (Class 2/4) applies if HMRC calls it self-employment trading income, but not if classified as investment income from an opaque entity
• Form 5472 is required every year, even with zero revenue. $25,000 penalty per missed form.
• A UK Ltd is simpler when clients are primarily in the UK. A US LLC adds value when you need US market credibility, USD settlement, or US banking
• Annual compliance for a UK-owned US LLC ($1,100-$3,000) runs roughly double a UK Ltd ($500-$1,500) because of dual-jurisdiction filings

References

• HMRC International Manual — Entity Classification (INTM180030) — HMRC's classification of US LLCs as opaque or transparent for UK tax purposes
• US-UK Double Taxation Convention (2001) — Full treaty text including Article 1(8) on fiscally transparent entities and Article 24 on non-discrimination
• Income Tax Act 2007, Part 13 — Transfer of Assets Abroad — TOAA rules that may attribute LLC income to UK residents
• HMRC Helpsheet HS263 — Foreign Tax Credit Relief — How to claim FTCR on Self-Assessment
• IRS Form 5472 Instructions (Rev. December 2024) — Filing requirements for foreign-owned US disregarded entities
• IRS Form SS-4 Instructions (Rev. December 2025) — EIN application process for non-residents
• IRS Form 8832 — Entity Classification Election — Electing corporate treatment for an LLC
• US-UK Totalization Agreement (SSA) — Social security coordination between the US and UK
• Companies House — Incorporate a Company — UK Ltd formation process and costs
• HMRC Self-Assessment (SA100) — UK tax return filing requirements for individuals with foreign income