Tax implications of operating a UK law firm from abroad

Flexible working and international mobility are now firmly embedded in many businesses’ growth plans. Law firms are no exception. Senior partners relocating overseas, overseas law firms establishing a UK presence, and “work from anywhere” policies can all deliver genuine commercial benefits.

However, when management or key decision‑makers are based outside the UK, unexpected UK tax issues can arise. These risks extend beyond corporation tax and can also affect employment taxes (PAYE and National Insurance), VAT, compliance obligations and longer‑term business planning.

Although the issues often overlap, tax risks tend to arise in two distinct situations:

UK‑established firms whose leadership is increasingly based overseas

Overseas firms looking to set up or expand into the UK

The underlying principles are similar, but the practical pinch points are often different.

In our experience, these issues rarely arise because of a single decisive change. More often, they develop gradually as a result of sensible commercial decisions, taken over time, without the tax implications being revisited as working patterns evolve.

When a UK law firm’s leadership moves overseas

For UK‑incorporated law firms, issues most commonly arise where senior partners or directors relocate abroad but continue to perform key management or decision‑making roles. This often happens gradually, particularly where remote working arrangements become semi‑permanent rather than exceptional.

From a UK perspective, a company is generally tax resident in the UK if it is incorporated here. However, overseas tax authorities apply their own domestic rules, which frequently focus on where the business is actually managed and controlled in practice (sometimes referred to as ‘effective management’ or ‘central management and control’).

Where senior individuals are living abroad and taking strategic or commercial decisions, an overseas tax authority may argue that the firm’s effective management has moved. This can result in the firm being treated as tax resident in more than one country at the same time, creating dual residence risk, which is not limited to corporate tax.

Overseas working can also trigger employment tax and social security issues. Even where individuals remain on a UK payroll, local rules may require overseas reporting, registrations or employer obligations if duties are performed outside the UK.

When overseas firms set up or expand into the UK

A different, but related, risk profile applies to overseas law firms establishing a UK presence. Creating a UK entity, opening an office or hiring UK‑based professionals does not automatically mean the UK will be treated as the primary taxing jurisdiction.

If strategic control, key commercial decisions or senior leadership remain firmly outside the UK, questions can arise around where profits should be taxed and whether the UK entity is genuinely operating as intended. In some cases, firms assume the UK company is UK tax resident and fully UK‑taxed, only to find that overseas tax authorities take a different view. It is rarely helpful when the first time this is considered is during a tax enquiry.

There can also be indirect tax considerations. Where services are provided across borders, or where firms operate through a mix of UK and non‑UK entities, there can be unexpected VAT outcomes if not considered upfront.

Understanding corporate tax residence and effective management

Corporate tax residence matters because it determines where a firm is taxed on its worldwide profits and which country’s tax rules apply in the first instance. It also affects access to double tax treaties and relief from double taxation.

Where a company is treated as tax resident in more than one country under domestic rules, the relevant double tax treaty will usually need to be consulted, and the tax authorities may need to engage with each other to determine the position. These assessments typically focus on where key management and commercial decisions necessary for the business as a whole are made.

In practice, this is a factual exercise. Tax authorities will look beyond formal documentation and focus on what actually happens day-to-day. Factors may include where senior leadership operates, where real decisions are taken, and where the business’s economic centre of gravity lies.

Key misconception and HMRC challenges

One of the most common misconceptions is that legal form alone determines the tax outcome. In reality, relying on incorporation documents, board minutes or stated policies can be risky if they do not reflect how the business genuinely operates.

HMRC and overseas tax authorities are increasingly willing to challenge arrangements that appear artificial or misaligned with commercial reality. For law firms, where senior individuals often combine ownership, management and professional roles, this risk can be particularly acute.

Permanent establishment risk

Separate from tax residence, overseas working can also give rise to permanent establishment exposure. This can arise where a firm has a fixed place of business overseas or where individuals habitually conclude contracts on its behalf from another country.

For professional services firms, this risk can arise more easily than expected, particularly where senior lawyers negotiate or agree client terms while abroad. A permanent establishment can trigger overseas tax registrations, profit attribution and local filing obligations, even if the firm remains UK tax resident. It may also carry indirect tax implications.

Compliance obligations and timing

When a firm’s working arrangements change, it is important to consider UK compliance implications early. These can include:

• ensuring corporation tax returns reflect the correct residence position

• managing PAYE, social security and employer obligations for overseas‑based staff

• reviewing VAT treatment of cross‑border services and registrations

• understanding whether a move could trigger a UK exit charge

Failing to address these issues promptly can lead to penalties, interest and prolonged engagement with tax authorities in more than one jurisdiction.

Manage tax risks early

Operating a UK law firm from abroad, or running a UK practice alongside overseas leadership, is not inherently problematic. However, it carries corporate tax, employment tax and indirect tax risks that should not be underestimated, particularly where arrangements evolve without deliberate planning.

If senior individuals are already working overseas, or overseas working is being actively considered, it is important to pause and review the tax position before arrangements become embedded. Common pressure points include where strategic decisions are taken and whether the firm’s overall management profile has shifted.

For overseas firms entering the UK market, similar risks can arise if leadership and decision‑making remain outside the UK, even where a UK entity has been established.

These matters are highly fact‑specific and can evolve quickly as working patterns change. Early advice can help identify potential exposure, clarify responsibilities in different territories and avoid unexpected tax and compliance consequences.

With careful structuring, clear governance and early professional advice, many of these risks can be managed effectively. Firms that engage early are far better placed than those forced to react once questions are raised by HMRC or overseas tax authorities.