International Services

International tax and advisory support for your global expansion

Expanding internationally brings opportunity, but also complexity. Our International Services team supports businesses at every stage, from setting up overseas operations to managing cross-border tax and compliance.

We combine technical expertise with practical insight, working with our global network to support you wherever you operate. With the right structure in place, we help you manage risk, minimise tax exposure and build a scalable international presence.

Working with an experienced adviser gives you clarity and confidence as you enter new markets. We help you reduce risk, ease administrative pressure and make better-informed decisions.

With the right support in place, you can focus on growth, knowing your operations are compliant and structured for the future.

Why Sumer?

Whether you're exploring new markets or refining your structure, our team is here to help.

Speak to Sumer

How we support your international operations

Private clients

We support international private clients, advising individuals and families on complex cross-border tax and wealth matters. This includes those relocating to or from the UK, as well as individuals with UK or overseas assets.

Navigating multiple tax regimes can be challenging, particularly where offshore structures such as trusts are involved. We provide clear, practical advice to help clients understand their position and plan effectively across jurisdictions.

Our work covers all key UK taxes, including income tax, capital gains tax and inheritance tax, helping clients manage their affairs with confidence.

Corporate tax

We advise on all aspects of corporate tax, from structuring and market entry to ongoing compliance. This includes corporate residency, transfer pricing and profit repatriation, helping you stay compliant and minimise double taxation.

VAT and customs

We support businesses managing VAT across multiple jurisdictions, from registrations and returns to structuring advice. We also advise on customs processes, import and export requirements, and goods classification.

International mobility

We help businesses and employees manage the complexities of working across borders, including tax residency, payroll obligations and international assignments.

Workforce tax and compliance

We advise on workforce related tax and compliance, including global mobility, labour supply chain risk and National Minimum Wage reviews. We also support HMRC enquiries and cross-border employment considerations. Our approach helps reduce compliance risk, identify cost-saving opportunities and strengthen workforce governance as your business grows.

Compliance

We help international businesses meet UK tax, accounting and statutory requirements, from initial setup through to ongoing reporting, ensuring your operations remain aligned with local regulations.

Expansion

We support businesses entering the UK or expanding overseas, providing practical advice on market entry, structuring and growth.

Company secretarial services

We provide support with company formations, statutory registers, governance and more complex corporate changes, helping ensure your UK entity is compliant and well managed.

Outsourced finance services

Our co-sourcing finance team supports your UK operations with bookkeeping, payroll, management accounts and VAT compliance, alongside optional fractional CFO support. This allows you to focus on running and growing your business.

Legal services

Sumer Law provides commercially focused legal support, from structuring and entity formation to employment law and governance, helping you operate with confidence in the UK.

International reach

Asia helpdesk

Our Asia helpdesk supports a wide range of Asian headquartered businesses with operations across the UK and Europe. Many operate through UK incorporated subsidiaries and act as regional hubs for cross-border activity.

These businesses span sectors including manufacturing, electronics and freight services. We support their operations by helping manage cross-border transactions and ensuring compliance with UK regulatory and financial reporting requirements.

We provide support across statutory audit, UK GAAP reporting, tax compliance and advisory, transfer pricing and corporate structuring. This includes managing the complexities of cross-border activity, such as intercompany transactions and alignment between UK and overseas tax regimes.

We also assist with company secretarial services, payroll, VAT compliance and HMRC engagement. For many clients, we act as a link between UK operations and parent companies in Asia, supporting reporting, consolidation and communication across jurisdictions.

Our team includes fluent Mandarin, Cantonese and Hindi speakers.

Gibraltar

Our Gibraltar office provides audit, tax and advisory services to businesses and individuals operating both locally and internationally.

Established over 20 years ago, the office has a strong track record of supporting a broad range of clients, including financial services firms, investment structures, trading companies and private clients. We provide statutory audit, financial reporting, tax compliance and advisory services.

We also advise individuals and families considering a move to Gibraltar, providing guidance on residence planning and the tax, regulatory and practical implications of relocating.

Our dedicated Gibraltar team is supported by specialists in our London office, enabling us to combine local expertise with wider technical knowledge and international experience.

Global network

As part of GGI, we connect you with advisers in over 125 countries, combining global reach with local expertise.

“Carpenter Box have been a key service provider to our substantial Group of companies for over 6 years, an extremely important part of our wider UK team. We have found their approach to our complex needs, and their advice as both proactive and flexible, and excellent value for money.

Having the ability to speak directly, and often, to the individuals working on our accounts, audit, tax and corporate finance specialists right up to the Partners is refreshing. This has saved so much time in ensuring everyone is on the same page in terms of our strategy and needs. I would definitely describe the firm as professional, proactive, approachable and friendly, great to work with and above all extremely competent in acting for us on their own initiative. Very satisfied with the relationship.”

Steve Shipp, Ferryspeed

International Services FAQs

What is international tax planning?

International tax planning helps individuals and businesses structure where multiple countries are involved. It can reduce tax risk, improve compliance and help you avoid unnecessary costs.

What is double taxation and can it be avoided?

Double taxation occurs when the same income, profits or gains are taxed in more than one country. This can happen, for example, when a business operates internationally or when individuals work or live across borders.

It can often be reduced or eliminated under UK domestic rules or through Double Taxation Agreements (DTAs) between countries. These agreements help determine which country has taxing rights and may allow relief for tax already paid overseas.

Do I have to pay UK tax on overseas income or gains?

You may need to pay UK tax on overseas income or gains if you are UK tax resident. Relief may be available through DTAs or by claiming foreign tax as a credit to prevent the same income being taxed twice.

What is a permanent establishment for tax purposes?

A permanent establishment (PE) is usually created when a business has a fixed presence or ongoing activity in another country. If a PE exists, the business may become liable for local corporation tax and reporting obligations on profits connected to those activities.

When does an overseas company need to pay UK corporation tax?

An overseas company may need to pay UK corporation tax if it has a permanent establishment or taxable activities in the UK. The rules depend on how the business operates, where contracts are concluded and the level of activity carried out in the UK.

What countries are in the OECD?

The Organisation for Economic Co-operation and Development (OECD) currently has 38 member countries, including the UK, United States, Canada, Australia, Germany, France, Japan and many other developed economies. The OECD plays a key role in shaping international tax policy, including transfer pricing guidance and global tax transparency initiatives.

What countries does the UK have double tax treaties with?

Although it changes from time to time, as new treaties are agreed, the UK has one of the largest networks with around 120 double tax treaties. Most of the UK treaties will follow the OECD ‘model treaty’ however many include variances meaning that the specific text of the treaty in question must be checked.

What is transfer pricing and does it apply to my business?

Transfer pricing rules apply when connected companies in different countries trade with each other. Businesses must ensure these transactions are priced on an “arm’s length” basis – meaning the pricing should reflect what independent parties would agree to commercially.

Can a non-UK company register for VAT in the UK?

Yes, overseas businesses can register for UK VAT even without a physical UK office. VAT registration may be required where goods or services are supplied in the UK, including through imports, warehousing or certain online sales activities.

What types of goods and services are exempt from VAT in the UK?

Certain goods and services are exempt from VAT in the UK, including some healthcare, education, insurance and financial services. VAT treatment can be complex, particularly for international businesses, so it is important to confirm how the rules apply to your activities.

What is the difference between VAT and customs duties?

VAT is charged on goods and services, while customs duties apply when goods are imported into a country. International businesses often need to manage both as part of cross-border trading and supply chain planning.

Do overseas companies need to run a UK payroll?

Depending on the jurisdiction of the employer and their presences in the UK an overseas businesses employing staff in the UK may need to register for PAYE and operate a UK payroll scheme. This can include obligations relating to income tax, National Insurance and workplace pensions.

What is the UK Statutory Residence Test?

The Statutory Residence Test determines whether an individual is considered a UK tax resident. It looks at factors such as time spent in the UK, work activity and personal ties to establish how UK tax rules apply.

Why is international tax advice important when expanding overseas?

International tax advice helps businesses enter new markets with confidence and avoid costly mistakes. Early planning can improve tax efficiency, reduce compliance risk and create a stronger foundation for long-term international growth.

Your International Services Champions

Whether you’re exploring new markets or refining your existing structure, our team is here to help.

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