US–UK BUSINESS ESTABLISHMENT & EXPANSION SERVICES
Launch and grow your business across borders with US UK Tax Advisors. We help US companies entering the UK and UK businesses expanding into the US with incorporation, tax registrations, and compliant structures—ensuring seamless setup and long-term growth under both IRS and HMRC rules.
Helping Businesses Expand Across Borders
Expanding your business between the US and UK opens new opportunities but also comes with complex legal, tax, and compliance challenges. At US UK Tax Advisors, we specialise in guiding companies, entrepreneurs, and SMEs through the process of establishing operations on either side of the Atlantic.
From company formation and tax registrations to business structuring and compliance, we ensure your expansion is efficient, fully compliant, and structured for long-term tax savings. Our team helps you avoid common pitfalls while building strong foundations for growth.
Whether you’re a UK company setting up in the US or a US business launching in the UK, our dual-qualified advisors simplify the process, reduce risks, and provide ongoing support so you can focus on growing your business confidently.
Our Services
Business Establishment & Expansion Services – US & UK Specialists
UK Business Setup for US Companies
End-to-end support with UK incorporation, Companies House registration, HMRC setup, and corporation tax compliance for US-based businesses expanding into the UK.
US Company Formation for UK Businesses
Guidance on US incorporation, IRS registration, and state tax requirements, helping UK businesses enter the US market with the right structure.
Entity Structuring & Incorporation (LLC, LLP, Ltd, Corp)
Advice on choosing and forming the most tax-efficient structure across the US and UK, tailored to your business goals.
Tax Registration & Compliance Setup
Full assistance with payroll, VAT, corporation tax, and state tax registrations to ensure smooth compliance from day one.
Expansion & Ongoing Advisory
Long-term support for international businesses, including tax planning, treaty relief, and compliance across multiple jurisdictions.
Banking, Payroll & Compliance Setup
Seamless setup of bank accounts, payroll, VAT, and tax registrations for businesses expanding between the US and UK, ensuring smooth operations and compliance.
Why Specialist Advisors Are Essential for US–UK Business Expansion
Expanding a business between the US and UK is more than a paperwork exercise—it's a highly technical process that involves tax, legal, and compliance risks. Without expert guidance, businesses can face double taxation, missed filings, or costly mistakes in structuring that limit growth.
By working with specialist US–UK business advisors, you gain access to professionals who understand both IRS and HMRC rules and the complexities of cross-border incorporation. From Form 5471 compliance to corporation tax returns, payroll setup, and VAT registrations, our team ensures your expansion is efficient, compliant, and aligned with your long-term goals.
A general accountant may manage domestic filings, but only a dual-qualified cross-border advisor can design tax-efficient structures, apply US–UK tax treaty reliefs, and coordinate compliance across two jurisdictions. Choosing specialists like US UK Tax Advisors protects profits, prevents penalties, and creates a solid foundation for international success.
Key Industry Insights:
45%
Of businesses expanding between US and UK cite tax complexity as their primary concern.
Source: International Business Expansion Survey 2023
35%
Average time savings for businesses using specialist cross-border advisors.
Source: Business Expansion Efficiency Report 2023
25%
Tax savings potential through proper structuring and planning.
Source: Cross-Border Business Tax Guide 2023
Get in Touch
Managing cross-border taxes doesn't have to be complicated. Whether you're a US citizen living in the UK, a UK resident with US tax obligations, or a business operating internationally, our team of specialist US UK tax accountants in London is here to help.
Expanding between the US and UK means choosing the right entity, completing the correct tax registrations, and structuring operations to manage permanent establishment and transfer pricing. We guide incorporation, HMRC and IRS registrations, VAT and US sales tax so your cross-border launch is compliant and efficient from day one.
Key Takeaways
- Subsidiary vs branch affects liability, corporation tax and profit flows
- A permanent establishment can create unexpected tax in the other country
- Intercompany charges must meet arm's-length transfer pricing rules
- VAT and US state sales tax are separate systems with their own thresholds
US–UK Cross-Border Tax: Key Facts
$10,000
Aggregate in foreign accounts at any point in the year triggers a mandatory FBAR (FinCEN Form 114) for US persons.
Source: IRS — FBARWorldwide
US citizens and Green Card holders must file a US return on worldwide income every year, regardless of where they live.
Source: IRS — Citizens Abroad$120,000+
The Foreign Earned Income Exclusion lets qualifying Americans abroad exclude over $120,000 of earned income (indexed annually).
Source: IRS — FEIE31 January
UK Self Assessment online returns and any tax owed are due by 31 January following the 5 April tax year end.
Source: GOV.UK — Self AssessmentUS–UK Business Expansion — Frequently Asked Questions
Should a US company set up a UK subsidiary or a branch?
A UK subsidiary is a separate company that limits liability and is taxed on its own profits, while a branch is an extension of the US parent and can create a UK permanent establishment. The choice affects UK corporation tax, US reporting and how profits and losses flow home. We model both so the structure fits your growth plans and tax position.
What tax registrations does a US business need to trade in the UK?
Depending on activity, you may need to register the entity with Companies House, register for UK corporation tax with HMRC, operate PAYE for UK employees, and register for VAT once you meet the threshold or from the outset in some cases. Getting registrations in place early avoids penalties and keeps your UK launch compliant from day one.
What does a UK company need to expand into the United States?
UK companies entering the US typically form a US entity such as a corporation or LLC, obtain an EIN, and register in the relevant states. US federal and state income tax, payroll taxes and sales tax obligations then apply based on where you have people, property or economic nexus. Structuring the US entity correctly protects the UK parent and simplifies profit repatriation.
What is a permanent establishment and why does it matter?
A permanent establishment (PE) is a taxable business presence — such as a fixed place of business or a dependent agent concluding contracts — that gives the other country the right to tax related profits. Inadvertently creating a PE through staff or an office abroad can trigger unexpected corporate tax. The US–UK treaty defines PE, and we help structure operations to manage it.
How is transfer pricing handled between US and UK group entities?
Transactions between related US and UK companies — services, licensing, financing or goods — must be priced on arm's-length terms and supported by documentation. Both the IRS and HMRC scrutinise intercompany pricing to ensure profit is not shifted artificially. We help set defensible policies so intra-group charges withstand review in both jurisdictions.
Do we need to register for VAT and US sales tax?
They are separate systems. UK and EU sales may require VAT registration and returns, while US sales tax is set state by state and triggered by physical or economic nexus. A business selling into both markets can face obligations in each. We assess where you have thresholds and nexus so registrations and filings are handled correctly on both sides.
Written & reviewed by the US-UK Tax Advisors cross-border tax team — chartered specialists in US and UK taxation, IRS and HMRC compliance, FATCA/FBAR reporting and double-taxation treaty planning.
Last reviewed: July 2026. This page is for general information and is not personal tax advice.