Fenton International

Fenton International is a private investment and advisory firm specialising in cross-border tax, global mobility, and people advisory. Founded by Mark Abbs, the firm provides independent advisory services for senior executives, corporate boards, HR and reward teams, finance and payroll functions, and professional advisers including tax, legal, immigration, and relocation firms. The firm coordinates advice across multiple disciplines and jurisdictions through an independent specialist network.

Service Capability

  • Cross-border tax advisory and structuring

  • Global mobility programme design and review

  • International executive relocation support

  • Share scheme and equity award taxation

  • Treaty analysis and relief claims

  • Non-resident director compliance

  • Short-term business visitor monitoring

  • Shadow payroll and international withholding

  • Permanent establishment risk assessment

  • Board and remuneration committee advisory

  • Expert witness and dispute support

  • AI-assisted compliance review (Fenton Insight)

Sector Experience

  • Financial services

  • Private equity

  • FinTech

  • Overseas banks operating in the UK

  • Life sciences

  • Luxury

  • Start-ups and scale-ups

  • FTSE 250

  • Small oil and gas

  • Disputes and expert witness matters

How The Firm Operates

Fenton International operates through Fenton Private Office, a private-office model for bespoke international advice. The model is structured around four offices: Private Executive Office, Employer Advisory Office, Private Board Office, and Professional Adviser Desk. Each office can be engaged through three service levels — Case Review, Lead Counsel, and Discovery — depending on whether the client needs senior review, full-service leadership, or structured discovery of risks and opportunities.

The firm coordinates independent specialists across tax, immigration, employment law, relocation, reward, payroll and technology through its international network, selecting the right adviser for each situation rather than drawing from a fixed panel.

FAQs

What does Fenton International do?

1

Fenton International provides independent cross-border tax, global mobility, and people advisory services for senior executives, boards, and international employers.


Who does Fenton International advise?

2

The firm advises individual clients (executives, directors, private company owners), in-house HR and reward teams, finance and payroll functions, governance bodies (boards, remuneration committees), procurement teams, and professional advisers including tax, legal, immigration, and relocation firms.


Where is Fenton International based?

3

Fenton International is based in London, with a registered address at 71-75 Shelton Street, Covent Garden, London WC2H 9JQ.


4

The firm operates an independent specialist network (Allstars Alliance) spanning tax, immigration, law, relocation, reward, and technology. It selects and coordinates the best adviser for each situation rather than drawing from a fixed panel.

How does Fenton International coordinate across multiple advisers?