International Tax

Cross-border tax fails at the seams: each country's advisor optimises their end, and the double charge, the missed treaty claim or the accidental permanent establishment happens in the gap between them. The rules themselves are less exotic than they look — residence tests, treaty articles, withholding mechanics — but they interact, and the interactions are where the money is lost.

Acumon advises across the seam: structuring UK operations for overseas groups, relieving double taxation for businesses and individuals with income in two systems, and coordinating with your advisors abroad so the whole position — not just the UK half — makes sense.

Inbound: Overseas Businesses Coming to the UK

The first UK decisions set the tax shape for years: subsidiary or branch, where management actually sits, how the UK entity is financed, and whether early UK activity has quietly created a taxable permanent establishment before anyone incorporated anything. We advise international groups at entry — structure, registrations, VAT position, employment obligations — and then run the UK compliance, working to head-office timetables and reporting formats. UK subsidiaries of international groups are a core part of the practice.

Double Taxation Relief and Treaty Claims

The same income taxed twice is usually a failure of paperwork, not of law: the UK's treaty network allocates taxing rights and relieves overlaps, but relief must be claimed — treaty residence certified, withholding taxes reduced at source or reclaimed, foreign tax credits computed correctly against UK liabilities. We handle the claims machinery in both directions, for companies receiving cross-border dividends, interest and royalties, and for individuals with employment or investment income spanning systems.

Cross-Border Individuals

For people, everything starts with residence: the statutory residence test decides UK exposure by day counts and ties, split-year rules govern arrival and departure years, and the post-domicile regime determines how foreign income and gains are taxed for new arrivals. We advise inbound executives, departing owners, and the internationally mobile in both directions — alongside our dedicated expatriate and non-dom services, which handle these situations as full specialisms.

Keeping the Structure Honest

Cross-border structures decay: intercompany charges drift from any defensible basis, financing that made sense at entry stops making sense, and rules keep moving underneath. We review intercompany arrangements against the arm's-length standard at the scale appropriate to your group, document what HMRC would ask to see, and coordinate with overseas advisors annually so both ends of the structure still agree what it is. Where a review reveals history to correct, our investigation specialists manage the disclosure.

What You Get With Acumon

• UK entry structuring: subsidiary, branch and permanent establishment analysis
• Full UK compliance for subsidiaries of overseas groups, to group timetables
• Treaty relief claims: withholding reduction, reclaims and foreign tax credits
• Statutory residence and split-year advice for cross-border individuals
• Intercompany arrangements reviewed and documented proportionately
• Cross-border VAT and employment tax handled by in-house specialists
• Coordination with your overseas advisors, not duplication of them
• Ex-HMRC insight on how cross-border positions are actually challenged

Why Acumon for International Tax?

• Many of the firm's qualified tax advisors previously worked for HMRC
• In-house Chartered Tax Advisor (CTA), qualified by the Chartered Institute of Taxation
• All 90 of the firm's professionals are based in the UK
• Dedicated ex-pat, non-dom and double taxation services in-house
• Supports UK subsidiaries of international groups, coordinating with overseas head offices

Get a Fixed-Fee Quote

Tell us what you need and we'll come back within one business day with a clear scope and a fixed price — no hourly-rate surprises. Call 020 8567 3451 or use the form and we'll be in touch.