International Tax Companies in the UK: Guide to Advisory Firms
AC
Acumon Chartered Accountants·18 min read
International tax has become an increasingly important consideration for businesses operating across borders. Whether a company is expanding into new markets, managing overseas subsidiaries or navigating the tax implications of international transactions, the right advice can help reduce risk while ensuring compliance with UK and international tax rules.
The UK is home to a diverse range of international tax advisory firms. Some focus on large multinational groups with complex cross-border structures, while others specialise in supporting growing businesses, family-owned companies, international investors or individuals with overseas interests. Each brings its own mix of technical expertise, sector experience and approach to solving international tax challenges.
This guide highlights a selection of firms providing international tax services in the UK. Rather than ranking providers, the aim is to offer practical context, looking at the types of services these firms provide, the organisations they typically work with and the areas where they have developed particular expertise. Whether you're reviewing your current tax arrangements or planning international growth, understanding the different strengths available in the market can help you identify the right adviser for your circumstances.
Acumon
Acumon is a UK firm of chartered accountants and advisors providing international tax services to companies, organisations and individuals across the UK.
The firm works with clients ranging from owner-managed businesses and international corporate groups through to entrepreneurs, investors and internationally mobile individuals. International tax services are designed to help clients manage cross-border tax obligations, optimise tax efficiency and maintain compliance with UK and overseas tax requirements.
Acumon provides international tax services across a broad range of cross-border matters, including international tax planning, double taxation advice, cross-border structuring, expatriate tax and overseas reporting obligations. Services are delivered using a practical, commercially focused approach tailored to each client's international activities, business structure and tax profile.
Acumon holds a Public Interest Entity (PIE) audit licence, enabling the firm to support organisations subject to enhanced regulatory oversight in the United Kingdom. In addition to its UK statutory audit registration, the firm also maintains audit licences in the Cayman Islands, British Virgin Islands (BVI), Jersey and Isle of Man, supporting clients with international structures and cross-border reporting requirements.
As businesses expand internationally and individuals become increasingly mobile, managing tax obligations across multiple jurisdictions becomes more complex. Acumon works with businesses, finance teams and private clients to develop practical international tax strategies while supporting compliance with evolving UK and overseas tax legislation.
International Tax Capabilities
Acumon provides international tax services across a wide range of business and personal tax environments.
These include:
international corporate groups
cross-border trading businesses
international investors
expatriates and internationally mobile individuals
overseas subsidiaries and holding companies
businesses with multi-jurisdictional tax obligations
International tax engagements are typically led by experienced tax professionals with direct involvement throughout the engagement.
Regulatory Licences and Registrations
Acumon holds several audit registrations that enable it to support organisations operating across multiple jurisdictions.
These include:
UK statutory audit registration
Public Interest Entity (PIE) audit licence
Jersey audit licence
Isle of Man audit licence
Cayman Islands audit licence
British Virgin Islands audit licence
These registrations allow the firm to support organisations operating across both the UK and key international financial centres.
Core Services
In addition to international tax services, Acumon provides a range of services that support financial reporting and governance.
These include:
international tax planning and cross-border tax advice
double taxation and expatriate tax services
statutory external audit
group and subsidiary audits
Public Interest Entity (PIE) audits
charity and not-for-profit audit
internal audit and governance reviews
risk management and compliance support
International tax work is often delivered alongside discussions with management, business owners and private clients regarding cross-border transactions, overseas investments, tax residency and international business expansion.
Many organisations and individuals seek international tax advice as they expand into overseas markets, establish international operations, relocate employees or manage investments across multiple jurisdictions.
Acumon works with clients that are:
expanding business internationally
managing cross-border tax obligations
establishing overseas group structures
planning international investments
reviewing global tax compliance requirements
Early engagement can help ensure that international tax planning, reporting obligations and cross-border compliance arrangements remain aligned with commercial objectives and applicable tax legislation.
Address: 1-2 Craven Road, Ealing, London, W5 2UA, UK
Phone: 020 8567 3451
Grant Thornton
Grant Thornton provides international tax services for businesses dealing with cross-border operations, overseas expansion and changing tax regulations. Their approach covers organisations at different stages of international growth, from companies entering foreign markets for the first time to businesses with an established presence across multiple countries. International tax advice is delivered alongside wider business and tax planning, helping clients consider tax issues as part of broader commercial decisions.
As international tax rules continue to evolve, the firm supports businesses with matters that often involve more than one jurisdiction. Access to specialists across the UK and through the Grant Thornton International network allows them to coordinate advice where cross-border transactions, reporting obligations or overseas structures require input from multiple countries. Their work reflects the practical challenges businesses face when managing international tax alongside day-to-day operations.
Key Highlights:
International tax support for UK and cross-border business activities
Advice covering businesses expanding into overseas markets
Access to specialists across multiple jurisdictions through an international network
Multi-disciplinary approach combining tax and wider business advisory
Experience with changing international tax legislation and compliance requirements
Support for businesses operating across different stages of international growth
Bishop Fleming advises businesses and individuals on international tax matters linked to overseas investment, cross-border business activity and global mobility. Their international tax services cover both corporate and personal tax considerations, recognising that international transactions often create obligations across several tax systems. The firm supports clients ranging from companies making their first overseas investment to multinational organisations and individuals with international assets or residency considerations.
International tax advice forms part of a broader tax offering that addresses issues such as transfer pricing, double taxation, international reporting and employment taxes. Through its membership of Kreston Global, Bishop Fleming works alongside independent firms in other countries when clients require coordinated advice across multiple jurisdictions. This enables businesses and individuals to manage international tax requirements while taking account of local rules in the countries where they operate.
Key Highlights:
International tax advice for businesses and private individuals
Support for overseas expansion and inbound investment
Experience with cross-border tax planning and reporting
Member of the Kreston Global network
Advice covering both corporate and personal international tax matters
Assistance with international workforce and mobility issues
Moore Kingston Smith supports businesses managing international tax issues arising from cross-border operations, overseas expansion and international group structures. Their international tax offering focuses on helping organisations understand tax obligations across different jurisdictions while addressing the practical considerations that come with international growth. Advice is provided for businesses entering new markets as well as those reviewing or restructuring existing international operations.
International tax services are supported through the wider Moore Global network, allowing clients to access local knowledge where projects involve multiple countries. Alongside strategic tax planning, the firm advises on international compliance requirements, transfer pricing, global mobility and indirect taxes. The emphasis is on helping businesses navigate changing international tax rules while maintaining appropriate reporting and governance across their operations.
Key Highlights:
International tax advice for businesses with cross-border operations
Support for overseas expansion and international restructuring
Access to global expertise through the Moore network
Advice covering international tax planning and compliance
Experience with OECD-related reporting requirements
International tax support alongside wider corporate tax services
Sheltons focuses on international tax advice involving more than one country, with services covering both businesses and private individuals. Their work centres on cross-border tax matters such as tax treaties, permanent establishment, residency, withholding taxes and international VAT. The firm has been advising on international tax since the mid-1990s and has developed its practice around complex issues that often involve multiple tax jurisdictions.
One aspect that distinguishes their work is the amount of collaboration they undertake with accounting and law firms that require specialist international tax input for their own clients. Alongside advisory work, the firm delivers international tax training, which reflects its involvement with technical aspects of international taxation and treaty interpretation. Their services are available across a range of international projects, from overseas investments to restructuring and cross-border employment matters.
Key Highlights:
Focus on international tax advisory across multiple jurisdictions
Advice for businesses, individuals and professional firms
Experience with tax treaty interpretation and cross-border taxation
International tax training alongside advisory services
Support for residency, withholding tax and permanent establishment matters
Address: 25 Eccleston Place, London SW1W 9NF, United Kingdom
Phone: +44 20 389 74 888
Kreston Reeves
Kreston Reeves provides international tax services for businesses expanding overseas, overseas organisations entering the UK market and individuals with cross-border tax considerations. Their international tax offering covers commercial activities across multiple jurisdictions, with advice linked to business growth, investment, acquisitions and international workforce planning. Support is available through their wider advisory practice, allowing international tax to be considered alongside corporate finance, legal and business planning where required.
Membership of the Kreston Global network enables the firm to coordinate advice with specialists in other countries when projects involve overseas operations. Their international tax team also works with private clients, helping individuals understand residency, domicile and cross-border tax obligations. Alongside planning work, they advise on transfer pricing, indirect taxes and international compliance requirements that arise as businesses grow internationally.
Key Highlights:
International tax advice for businesses and private individuals
Support for UK outbound and inbound investment
Member of the Kreston Global network
Cross-border tax planning linked to wider advisory services
Experience with international business expansion and mobility
International tax support across multiple jurisdictions
Services:
International business tax
Cross-border tax planning
Transfer pricing
International tax structuring
Global mobility tax
Residency and domicile advice
VAT and duty advisory
International compliance support
Tax planning for overseas investments
Cross-border transaction advisory
Intellectual property tax structuring
International financing structures
Contact Information
Website: www.krestonreeves.com
Twitter: x.com/KrestonReeves
LinkedIn: www.linkedin.com/company/kreston-reeves
Address: 2nd Floor, 168 Shoreditch High Street, London, E1 6RA
Phone: +44 (0)330 124 1399
UHY
UHY provides international tax services for businesses involved in overseas trade, cross-border investment and international group structures. Their advice focuses on the tax issues that arise when organisations operate across different countries, helping clients consider tax planning alongside commercial decisions such as acquisitions, mergers, overseas branches and international expansion. International tax specialists work with colleagues across the wider UHY network, giving clients access to local knowledge in many jurisdictions.
Cross-border employment is another area of their international tax practice. Businesses relocating employees overseas or bringing staff into the UK can receive support with tax, social security and reporting obligations that often accompany international assignments. Alongside advisory work, UHY also publishes practical country guides covering business and tax considerations in different parts of the world.
Key Highlights:
International tax support for cross-border business activities
Access to advisers through the UHY international network
Advice covering overseas expansion and corporate restructuring
Experience with international employee taxation
International tax planning for businesses trading overseas
Country-specific business and tax guidance available
Address: Glenewes House, Gate Way Dr, Yeadon, Leeds
Phone: +44 113 257 4506
PEM
PEM advises businesses and individuals on international tax matters connected with overseas trade, investment and global mobility. Their international tax team supports UK businesses expanding abroad, overseas companies investing in the UK and individuals with tax obligations across more than one country. Advice covers both commercial and personal tax considerations, reflecting the different challenges that arise when people or businesses operate internationally.
As a member of Kreston Global, PEM can work with firms in other jurisdictions where international projects require local expertise. Their international tax services cover business structuring, employment tax, overseas VAT and personal tax matters, helping clients understand reporting requirements and cross-border tax rules without separating these issues from wider business planning.
Key Highlights:
International tax advice for businesses and private individuals
Support for UK outbound and inbound investment
Member of the Kreston Global network
Cross-border tax guidance across multiple jurisdictions
Advice covering corporate and personal international tax matters
Experience with overseas VAT and employment tax issues
Address: Salisbury House, Station Road, Cambridge, CB1 2LA
Phone: 01223 728222
RSM
RSM advises businesses on international tax matters linked to overseas operations, cross-border transactions and global compliance. Their international tax services are designed for companies with an international presence, whether they are entering foreign markets for the first time or managing established operations across several jurisdictions. The focus is on helping businesses understand how tax fits into wider commercial decisions while meeting local and international obligations.
International tax advice is supported through collaboration across the firm's global network, allowing different jurisdictions to be coordinated when required. Alongside strategic tax planning, the team covers compliance, transfer pricing, VAT, international reporting and global mobility. Businesses expanding into the UK can also receive guidance on tax structures, payroll obligations and the practical tax considerations involved in establishing a UK presence.
Key Highlights:
International tax support for cross-border business activities
Advice for businesses expanding into and out of the UK
Access to specialists through the RSM global network
International tax planning linked with compliance and reporting
Support with UK tax governance and overseas operations
Cross-border advisory for businesses of different sizes
Services:
International tax advisory
Cross-border tax planning
Transfer pricing
Pillar Two advisory
Global tax compliance
International VAT compliance
Global mobility tax
UK market entry tax support
Holding company structuring
Local payroll tax guidance
Tax registrations
International reporting coordination
Contact Information
Website: www.rsmuk.com
LinkedIn: www.linkedin.com/company/rsm-uk
Instagram: www.instagram.com/rsm.uk
Address: 4th Floor, The Capitol, 431 Union Street,Aberdeen, AB11 6DA
Phone: +44 (0)1224 321133
BDO
BDO provides international tax services for businesses operating across multiple countries or planning to expand into new markets. Their international tax team advises organisations on the tax implications of overseas growth, business restructuring and international investment, helping businesses manage tax obligations across different jurisdictions while keeping commercial objectives in view.
Cross-border tax advice forms part of a wider corporate tax offering covering transfer pricing, withholding taxes, international VAT and employment taxes. Through the BDO international network, clients can access local tax knowledge where projects involve several countries. The firm's international tax practice also covers OECD developments, BEPS initiatives and transaction-related tax matters connected with acquisitions, financing and corporate restructuring.
Key Highlights:
International tax advice for cross-border business operations
Support for overseas expansion and international restructuring
Global network covering multiple jurisdictions
Experience with OECD and BEPS-related tax matters
International tax planning alongside corporate transactions
Transfer pricing and cross-border compliance support
KPMG advises multinational organisations on international tax issues arising from global operations, business transformation and changing regulatory requirements. Their international tax services focus on helping businesses manage tax across multiple jurisdictions while responding to developments such as BEPS Pillar Two, digital business models and evolving reporting obligations. International tax is considered alongside broader commercial decisions including expansion, restructuring and investment.
Technology forms an important part of their international tax approach, supporting reporting, modelling and compliance across different territories. The firm's international tax practice covers areas including mergers and acquisitions, post-acquisition integration, legal entity simplification, digital taxation and international financing. Advice is delivered through a global network with local knowledge across individual markets.
Key Highlights:
International tax support for multinational organisations
Focus on cross-border compliance and tax strategy
Global network with local jurisdiction expertise
Technology-enabled international tax services
Advice covering business transformation and expansion
Support for evolving international tax regulations
Haines Watts offers international tax planning as part of its wider tax advisory services for businesses with overseas interests. Their international tax support is aimed at organisations expanding beyond the UK or managing tax issues that arise from trading across different countries. The emphasis is on helping businesses consider international tax as part of their wider commercial and financial planning.
Businesses looking to establish or grow an international presence can access advice that takes account of cross-border tax obligations and changing regulatory requirements. International tax planning sits alongside broader business advisory services, allowing overseas growth, investment and tax matters to be considered together where appropriate.
Key Highlights:
International tax planning for businesses with overseas activities
Support for companies expanding into international markets
Cross-border tax advice as part of wider tax advisory services
Focus on international business growth and planning
Guidance on international tax obligations
International tax integrated with broader business advice
James Cowper Kreston supports businesses and individuals dealing with international tax matters connected with overseas expansion, inbound investment and cross-border mobility. Their international tax practice covers organisations taking their first steps into foreign markets as well as established businesses operating across multiple jurisdictions. Advice is tailored to the circumstances of each client, recognising that international tax requirements vary depending on where and how a business operates.
Access to the Kreston Global network allows international projects to be coordinated with local specialists when advice is needed in more than one country. Alongside business tax, the firm advises on international personal tax and expatriate matters, helping businesses and individuals understand the tax implications of working, investing or relocating across borders.
Key Highlights:
International tax advice for businesses and individuals
Support for UK outbound and inbound investment
Member of the Kreston Global network
Cross-border tax planning across multiple jurisdictions
International personal tax and global mobility expertise
PwC provides international tax services for multinational organisations managing cross-border operations, international growth and changing regulatory requirements. Their international tax offering covers business expansion, restructuring, financing and cross-border transactions, helping organisations understand tax obligations across multiple jurisdictions while responding to developments such as OECD Pillar Two.
Technology plays a significant role in the firm's international tax approach, supporting compliance, modelling and reporting across global operations. International tax specialists advise on business transformation, tax structuring and international transactions, with services designed to address the practical tax implications of operating in an increasingly complex global environment.
Key Highlights:
International tax services for multinational organisations
Support for cross-border operations and expansion
Focus on international compliance and regulatory developments
Technology-enabled international tax solutions
Experience with OECD Pillar Two requirements
Global network supporting multi-jurisdiction projects
Lovewell Blake advises individuals on international tax matters connected with living, working or holding assets in more than one country. Their international tax services focus on personal tax issues such as residency, domicile, overseas income and double taxation. Advice is tailored to individual circumstances, recognising that international tax rules often depend on personal residency, income sources and long-term plans.
Membership of HLB International enables the firm to obtain support from advisers in other jurisdictions when cross-border matters extend beyond the UK. Alongside tax planning, they assist with payroll considerations, overseas income, inheritance tax and the tax treatment of international assets, helping individuals understand their obligations before and after moving between countries.
Key Highlights:
International tax advice focused on private individuals
Guidance on residency and domicile matters
Support for people living or working overseas
Member of the HLB International network
Advice covering overseas income and cross-border taxation
Address: Bankside 300, Peachman Way, Broadland Business Park, Norwich, NR7 0LB
Phone: (01603) 663300
Conclusion
The right international tax adviser will depend on the nature of your business, where you operate and the type of cross-border issues you need to address. Some firms specialise in supporting multinational groups with complex international structures, while others focus on growing businesses, private companies or individuals with overseas tax obligations. Their experience, international reach and areas of technical expertise can vary significantly.
When comparing advisers, it is worth considering more than the list of services they provide. Experience with businesses similar to yours, access to international networks, understanding of local tax rules and the ability to coordinate advice across multiple jurisdictions can all influence the support you receive. For many organisations, it is equally important to work with advisers who understand broader commercial objectives alongside tax compliance and reporting requirements.
This guide highlights a selection of firms providing international tax services in the UK. It is intended to help businesses and individuals understand the different approaches available, making it easier to identify an adviser whose experience and capabilities match their international tax requirements.
AC
Written by the Acumon team
Acumon is an ICAEW-registered firm of chartered accountants and registered auditors
based in London, with offices in Pitstone, Aylesbury and Bournemouth. Need advice on
anything covered here? Talk to us.
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