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 process is straightforward. The tax picture is not. Since April 2025, HMRC classifies US single-member LLCs as "opaque" — meaning corporation-like for UK tax purposes — even though the IRS treats them as transparent (disregarded). This mismatch creates a structural tax trap: LLC income may be taxed in both the US and the UK, with treaty relief under Article 24 of the US-UK Double Taxation Convention providing incomplete protection. Most formation guides do not mention this because formation services have no incentive to explain what happens after the sale.

I have operated cross-border entities between the US and multiple jurisdictions for nearly two decades. The UK-US LLC mismatch is not new — HMRC has long had reservations about how to classify LLCs — but the formal shift to "opaque" treatment in 2025 turned a gray area into a defined compliance obligation. This guide walks through the five mechanical steps to form and operate a US LLC from the UK, followed by the HMRC classification issue that makes this structure more complex for UK residents than for founders in most other countries.

Step 1: Choose a State

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

For most UK solo founders, Wyoming is the practical default. The combination of $100 formation + $60/year annual report, explicit single-member charging order protection, and no state income tax makes it the lowest-friction option. Formation services like Doola, Firstbase, and Northwest all offer Wyoming formation.

Delaware makes sense in one scenario: raising venture capital from US-based investors. The Court of Chancery and the body of Delaware corporate case law are what US institutional investors and their attorneys expect. For a UK freelancer billing through Stripe or a bootstrapped SaaS founder, this legal infrastructure adds ~$240/year in additional state fees without practical benefit.

A full side-by-side analysis of Delaware vs Wyoming for non-residents covers the nuances in detail.

Step 2: Form the LLC

Formation requires three components:

1. Registered agent — A US-based person or company that receives legal and tax documents on behalf of the LLC. Required in every state. Annual cost ranges from $50 to $300 depending on the provider. This address appears on the LLC's public state filing.

2. Articles of Organization — Filed with the state secretary of state. Lists the LLC name, registered agent, and basic structural information. Most states process filings within 1-5 business days. Expedited processing (24-48 hours) is available in most states for an additional fee.

3. Operating Agreement — Not filed with the state but legally important. Defines ownership, management structure, and profit distribution. Single-member LLCs still benefit from having one — it establishes the separation between personal and business assets. US banks frequently request this document during account opening.

UK residents face no nationality restrictions. No US state restricts LLC formation based on citizenship or residency. A UK passport is accepted as the primary identification document throughout the process.

Formation services handle all three steps. Pricing ranges from $297 to $500 for the initial formation package, with annual renewals of $199 to $399 depending on the service tier. Full cost breakdown of formation services.

Step 3: Get an EIN from the UK

An Employer Identification Number (EIN) is the LLC's federal tax ID. It is required for opening a US bank account, filing tax returns, and connecting payment processors. UK residents can obtain an EIN without an SSN or ITIN.

Three methods, ranked by processing time:

Key fields on Form SS-4 for UK residents:

• Line 7b (SSN/ITIN of responsible party): Enter "FOREIGN" — no SSN or ITIN is needed
• Line 4a-b (Mailing address): A UK address is acceptable
• Line 16: Check the box indicating the responsible party's address is outside the US

The phone method is the fastest option for UK-based founders. The time zone offset is manageable — calling at 11:00 AM GMT reaches the IRS at 6:00 AM Eastern when hold times tend to be shortest. The full process for each method is covered in How to Get an EIN Without an SSN.

Step 4: Open a US Bank Account

UK founders face fewer banking barriers than founders from most other countries. The UK is not on any OFAC sanctions list, UK passports are universally accepted for identity verification, and UK addresses carry no additional compliance flags with US fintech platforms.

Current options for UK nationals:

For UK founders specifically, Wise Business offers a structural advantage: the ability to hold and receive GBP alongside USD in the same account. A UK founder billing US clients in USD and paying UK expenses in GBP can manage both currencies without external transfers. Mercury provides a stronger US banking feature set (treasury, credit cards, integrations) but operates in USD only — requiring a separate transfer to move funds to a UK account.

A detailed comparison of Mercury, Wise, and Relay covers fees, features, and the account opening process for non-residents.

The HMRC Trap: Why UK Residents Face a Unique Problem

Everything above — state selection, formation, EIN, banking — works identically for UK founders as it does for founders from any other country. The steps are mechanical. They work.

What follows is where the structural risk specific to UK residents lives. HMRC's classification of US LLCs creates a tax mismatch that does not exist for founders in most other jurisdictions.

The Classification Mismatch

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

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

Why This Creates Double Taxation Risk

The problem is mechanical. Take a UK resident who operates a US single-member LLC earning $100,000 in revenue 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 — for example, the founder performs services while physically present in the US — US tax applies.

UK side (HMRC): HMRC treats 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 from the LLC as dividend income when profits are distributed to the UK owner — even though the IRS treats the same distribution as a non-event (since the LLC is disregarded, 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 is treated as a "person abroad" to whom income has been transferred
3. Apply the Controlled Foreign Company (CFC) rules in limited circumstances — though these primarily target UK companies, not individuals

The Treaty Does Not Fully Resolve This

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

• Article 1(8) of the treaty states that income derived 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 the domestic tax law of that State.
• Since HMRC treats the LLC as opaque, it does not treat the LLC's income as the UK resident's income under domestic law. This breaks the mechanism that would otherwise provide treaty relief.
• The result: The UK owner may not be eligible to claim Foreign Tax Credit Relief (FTCR) in the UK for US taxes paid on the LLC's income, because HMRC does not recognize the income as belonging to the individual. Conversely, if HMRC taxes the distributions as dividends, the US does not recognize a dividend event (because the LLC is disregarded), so there is no US tax to offset.

This circularity — where each country's classification prevents the other country's tax relief mechanism from activating — is the core of the HMRC trap.

What This Means in Practice

For a UK resident operating a US single-member LLC:

• If the LLC earns income that is not ECI (no US tax due): HMRC may still tax distributions from the LLC or attribute the LLC's income to the owner under TOAA rules. No double taxation occurs in this case — but the UK tax treatment may be less favorable than if the income had been earned through a UK structure, because dividend treatment and TOAA attribution carry different rates and allowances than trading income.

• If the LLC earns ECI (US tax applies): Both countries may tax the same economic income — the US taxes it as pass-through income of the disregarded entity, and the UK taxes it either as dividend distributions or under TOAA attribution. Foreign tax credit relief may be unavailable or incomplete because HMRC does not match the income to the same category the IRS uses.

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

Self-Assessment Obligations

UK residents are taxed on worldwide income. A UK resident operating a US LLC reports the income through the Self-Assessment (SA100) tax return, regardless of whether funds are remitted to the UK.

What to Report

Foreign Tax Credit Relief (FTCR)

If US tax has been paid on the LLC's income — either because the income is ECI or because US withholding applies — the UK owner may claim Foreign Tax Credit Relief to offset the UK liability. FTCR is claimed on form SA106.

The limitation: FTCR applies only when the same income is taxed in both countries and the income is recognized as the individual's income under UK law. If HMRC classifies the LLC as opaque and re-characterizes the income (e.g., treating it as dividends rather than trading profits), the credit may not align with the US tax paid on a different characterization of the same economic income.

HMRC's guidance on FTCR (HS263) covers the mechanics. For LLC-specific treatment, INTM180030 and the surrounding manual pages address entity classification.

Filing Deadlines

Both countries require annual filings. The US filing (Form 5472) is required even if the LLC has 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 have National Insurance Contributions (NIC) obligations. The classification depends on how HMRC treats the LLC income.

Class 2 and Class 4 NIC

If HMRC classifies the LLC income as self-employment trading income — which is more likely when the UK owner is actively performing services through the LLC — Class 2 and Class 4 NIC apply on the profits.

If HMRC classifies the LLC income as investment/dividend income from an opaque entity — Class 2 and Class 4 NIC do not apply, because NIC is charged on earned income from a trade, not on investment income.

The distinction matters. A UK founder earning $80,000 through a US LLC faces a materially different NIC bill depending on whether HMRC treats that income as trading profits or as distributions from an opaque entity. The irony is that the opaque classification — which creates the double taxation risk described above — also removes the NIC liability, while the transparent classification that would simplify the income tax picture triggers NIC.

The US-UK Social Security Totalization Agreement

The US-UK Totalization Agreement prevents double social security contributions. Under the agreement, a self-employed individual is generally subject to social security contributions in the country where they reside. A UK resident operating a US LLC would pay NIC in the UK, not US self-employment tax (Social Security + Medicare).

This applies only if the individual is self-employed. If the LLC income is classified as investment income by HMRC, the Totalization Agreement is not relevant — there is no self-employment to assign.

UK Ltd vs US LLC: When Each Structure Makes Sense

For UK residents, the choice between a UK Ltd and a US LLC is not about formation — it is about where the structural weight of the business sits.

When a UK Ltd is the simpler structure

• The founder's clients are primarily in the UK or Europe
• Revenue is denominated in GBP or EUR
• The founder wants a single-jurisdiction compliance obligation
• The business is services-based with no specific need for US banking or US market positioning
• IR35 considerations drive the need for a corporate structure (UK Ltd is the standard vehicle)

When a US LLC adds structural value

• The founder's clients are primarily in the US and pay in USD
• US market credibility matters — B2B SaaS buyers, enterprise procurement, or US partnership agreements that favor US-domiciled entities
• The founder needs US banking infrastructure (ACH, domestic wires, US checking account) for operational reasons
• The founder is building a product business with US-based revenue that will scale beyond services

When both are needed

Some UK founders operate both: a UK Ltd for UK/EU clients and a US LLC for US clients. This adds compliance complexity (two sets of filings, intercompany transfer pricing considerations) but cleanly separates the 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 a UK address are sufficient for formation, EIN application, and bank account opening. No visa, no SSN, and no US visit is required.

How does HMRC classify a US single-member LLC?

HMRC classifies a US single-member LLC as an opaque entity — similar to a corporation — for UK tax purposes. This classification is based on UK domestic law, not US tax law. The IRS treats the same entity as a disregarded entity (transparent). This classification mismatch is the source of the tax complexity described 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 has no US income tax liability on business profits. The LLC is disregarded for US tax purposes, 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. However, if the income is ECI — for example, the founder performs services while physically in the US — US tax applies.

What is the total annual compliance cost?

This is the ongoing cost after formation. Year 1 adds $297-$500 for the formation service. A UK Ltd, by comparison, costs approximately $500-$1,500/year in total compliance.

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

A single-member LLC can elect to be treated as a corporation for US tax purposes by filing IRS Form 8832 (Entity Classification Election). This would make the LLC a C-Corp for US purposes. HMRC already treats the LLC as opaque (corporation-like), so both countries would then agree on the classification. The trade-off: the LLC would owe US corporate income tax (21% federal) on its profits, plus a second layer of tax when profits are distributed to the UK owner. Whether this produces a better overall tax outcome than the current mismatch depends on income levels, profit retention plans, and treaty credit calculations. This is a decision that requires professional tax advice specific to the individual's circumstances.

Key Takeaways

• US LLC formation for UK residents is mechanically identical to any other non-resident: state filing, EIN by phone or fax, remote bank account through Mercury or Wise, and operational within 2-8 weeks
• Wyoming at $100 + $60/year is the practical default for UK solo founders not raising US venture capital
• UK founders face easier US banking access than founders from most other countries — Mercury, Wise Business, and Relay all accept UK applicants without friction
• HMRC classifies US single-member LLCs as opaque entities since April 2025 — this creates a classification mismatch with the IRS that may result in incomplete treaty relief and unfavorable tax characterization
• The US-UK treaty does not fully resolve the classification mismatch because HMRC does not recognize LLC income as the individual's income under UK domestic law
• UK residents report worldwide income through Self-Assessment (SA100) — LLC income goes on SA106 (Foreign), with classification as either trading or investment income depending on HMRC's view
• National Insurance (Class 2/4) applies if HMRC classifies the LLC income as self-employment trading income, but not if classified as investment income from an opaque entity
• Form 5472 is required by the IRS every year, even with zero revenue — the $25,000/year penalty for non-filing is the largest US-side compliance risk
• A UK Ltd is structurally simpler for founders whose clients are primarily in the UK; a US LLC adds value when US market credibility, USD settlement, or US banking infrastructure is needed
• The annual compliance cost for a UK-owned US LLC ($1,100-$3,000) is roughly double that of a UK Ltd ($500-$1,500) because of dual-jurisdiction filing obligations

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