International tax, payroll, reward & Global Mobility advisory.
Fenton International advises HR teams & directors, global mobility managers, reward teams, and recruitment functions on the tax, payroll, social security, pension, long term incentives, shares, policy & strategy relating to international employees and directors. We help employers manage international employee moves, remote working arrangements, international assignments, international business trips & commuting, overseas NEDs, disputes, audits and relocations. This includes identifying employer and employee obligations, reducing risk, and coordinating specialist input where tax, immigration, and employment law interact.
How we support you & your executives.
Three levels of support are available.
Case Review
Senior judgement on analysis or positions already prepared by your team or another adviser.
Lead Counsel
Full-service advice where Fenton leads the analysis, co-ordinates specialist input across tax, payroll and reward, social security, immigration, legal and provides a clear recommended position.
Discovery
Structured review of payroll records, travel data, employment arrangements or equity records to identify cross-border tax, social security, immigration or reward risks and opportunities across your mobile population.
When this needs immediate attention.
An employee is already working from another country without a cross-border review
Payroll, tax, social security, immigration, and permanent establishment exposure may already have arisen. Permanent establishment means an employee's presence may create corporate tax obligations for the employer.
The longer the arrangement continues unreviewed, the more jurisdictions and obligations may be affected.
A senior executive relocation is imminent or underway
Tax, payroll, equity, social security, reward, and immigration decisions may need to be fixed before contract signing or start date.
Planning options narrow significantly once contracts are signed and moves have begun.
An executive has complained about service from an adviser, unexpected tax costs or double taxation
The employer may face reputational damage, retention risk, and potential liability depending on the mobility policy and tax equalisation position.
Resolving the position quickly protects both the employee relationship and the employer's governance position.
Immigration approval has been obtained but the tax and payroll position has not been reviewed
The employee may start work before the employer has met its payroll registration, withholding, or social security obligations.
Tax, payroll, and immigration timing need to be coordinated — immigration approval alone does not resolve the employer's tax obligations.
The business has no remote working policy or the existing policy is being breached
Ad hoc overseas working arrangements may be creating obligations the employer has not identified or documented.
A policy review now prevents individual arrangements from creating uncontrolled cumulative exposure.
Multiple advisers — tax, immigration, relocation, reward — are involved but no one holds the overall position
HR may receive conflicting or incomplete advice, with no single defensible position to act on.
Coordinating specialist input into one position makes things less complex, reduces the risk of gaps, conflicts, and governance failures.
Your issues → Fenton support → typical output.
Remote worker risk review
Assessment of tax, payroll, social security, immigration, and permanent establishment risk, with recommendations.
Assignment tax and mobility advisory
Analysis of employer obligations, employee tax position, social security, and cost projection.
Executive mobility review
Coordinated pre-move analysis covering tax, payroll, equity, social security, reward and immigration timing.
Short-term business visitor compliance review (includes business trips, commuters, remote workers and project employees)
Assessment of PAYE and reporting obligations, Appendix 4 eligibility, and recommended tracking controls.
Mobility policy advisory
Policy review or drafting covering tax equalisation, hypothetical tax, cost allocation, and governance. Fenton can draft bespoke tax equalisation type arrangements to fit your exact needs.
Cross-border equity and reward review
Analysis of taxing rights per jurisdiction, employer withholding obligations, social security, and employee impact (tax advantage status, elections, valuations and timing).
Pre-hire cross-border review
Analysis of impact of the UK role on the employee before the offer. Advice on employer registrations, payroll, withholding, and social security obligations before the hire starts. Fenton can speak with the candidate to answer questions and try to relieve any concerns.
Multi-adviser coordination
Integrated position identifying gaps, conflicts, and a single recommended course of action. Simplification wherever possible.
Other HR & reward services we provide.
Support you with compliance, planning, strategy and costs relating to employees working remotely from another country, creating tax, payroll, or social security exposure (business trips, commuters, remote workers, senior employees working remotely from overseas, project workers, short and long assignments, local transfers, localisations and repatriations).
Mobility policy design, tax strategies, global talent & reward strategies
Assignment cost management
Business travellers, international commuters and remote workers: policy, monitoring, tracking and compliance obligations.
Help with employee communications on complex cross-border matters
Support with vendor management and selection
Fractional HR support for managing a small number of mobile employees
Global share plan reporting, tracking, monitoring and reporting (particularly where complex or bespoke arrangements in place)
What a proper answer needs to cover.
Personal tax residence of the employee in each relevant country
Employer payroll, withholding, and reporting obligations in each jurisdiction
Social security — which country's regime applies and whether an A1 certificate or Certificate of Coverage, confirming the applicable social security legislation, is needed
Immigration status and its interaction with tax and payroll timing
Employment law position, meaning which jurisdiction's employment law governs the arrangement
Equity, share plans, and deferred compensation across borders
Mobility policies — assignment types and whether tax equalisation, hypothetical tax, or other cost-sharing arrangements apply
Corporate tax and permanent establishment risk arising from the employee's presence
Which specialist — tax, immigration, legal, relocation, reward — is responsible for which part of the answer
Practical implementation — who does what, by when, and what documentation is needed
HR & mobility FAQs.
01 Can an employee work remotely from another country?
It depends on the arrangement. An employee working from another country — even informally or for short periods — may create tax, payroll, social security, pension, immigration, and corporate tax obligations for the employee and employer in that country. The answer requires a cross-border review of the specific facts: which country, how long, what duties, how senior the employee is, what is the employment and payroll structure, and what immigration permissions exist.
02 What should HR check before approving an international assignment or remote working request?
HR should confirm the tax, payroll, social security, equity, pension and immigration position before the arrangement begins — not after. Key questions include: where does the employee pay tax, does the employer need to register for payroll in the host country, which country's social security applies, is an A1 or Certificate of Coverage needed, what are the employee's personal tax obligations, how are pension contributions treated, how are long term incentives treated and reported and does the arrangement create permanent establishment risk for the employer.
03 What is tax equalisation and when is it needed?
Tax equalisation is an employer policy under which the employee pays no more and no less tax than they would have paid had they remained in their home country. The employer bears the cost of any additional tax arising from the international working arrangement. It is commonly used for international working arrangements where the employer wants to ensure the employee is not financially disadvantaged by the move. There are many variations including tax protection, tax gross-up and a bespoke approach can be designed for most arrangements and payments.
04 What should HR do if an employee has already been working overseas without a cross-border review?
Take advice before making changes to the arrangement. The employer may already have payroll, tax, social security, or immigration obligations in the country where the employee has been working. A retrospective review can identify the obligations that have arisen, quantify the exposure, and recommend whether to regularise the position, amend the arrangement, or bring the employee back.
05 How should HR coordinate tax, legal, immigration, and relocation advice for a senior executive move or overseas working arrangement?
The timing and sequencing of tax, payroll, legal, immigration, and relocation decisions are closely connected. Immigration applications, tax residence start dates, equity vesting, contract terms & obligations and relocation logistics all affect each other. HR should ensure a single adviser or coordinator holds the overall position and that specialist advice from separate firms is integrated before decisions are finalised — rather than reconciled afterwards.
Credentials and related insights.
The Fenton Employers Desk is led by Mark Abbs, a senior international tax adviser with more than 32 years’ experience, with 14 years as Tax Partner, Head of International and Senior Leadership Team member at a UK Top 8 firm. Over 16 years as a Senior Adviser in Big 4 firms (PwC, EY). He is a Fellow of the Association of Taxation Technicians, an IRS Enrolled Agent, and an accredited expert witness.
Our Advisory team has held multiple senior leadership and board-level positions in HR, reward, and governance, managing budgets, delivering and setting strategy, and boardroom scrutiny. We bring the practical judgement of people who have owned the problem — not only advised on it.
