Employees Working on a UK Construction or Installation Project

If your business is involved in a long-term construction or installation project in the UK, and employees from your overseas head office or another group company are sent to work in the UK, there are important tax considerations you must not overlook.

We work with clients across a range of industries and project types, including:

  • Renewable energy installations (wind, solar, hydro, biomass, and biogas)
  • Power generation infrastructure (including nuclear)
  • Manufacturing plant installations and engineering works
  • Assembly and commissioning of machinery and production lines
  • High-voltage or electrical substation work
  • IT systems implementation and data centre fit-outs


Many of these projects start as short-term assignments, but as plans evolve and the scope of work increases, the duration may extend beyond 12 months. Once this happens, a UK Permanent Establishment (PE) arises under the terms of the applicable double tax treaty. When that occurs, the UK not only has taxing rights over the business profits of the PE — it also has taxing rights over the employment income of any individuals working on the UK project.

This includes workers carrying out project supervision, quality assurance, installation oversight, commissioning roles, or providing technical input. Whether your project is in construction, infrastructure, renewable energy, or advanced manufacturing — if your overseas staff are contributing on-site in the UK, there is a high likelihood that their income is taxable here.

Common Misconceptions

One of the most frequent mistakes we see is the assumption that UK income tax obligations only arise if an employee is in the UK for 183 days or more. This is not true. The correct approach is to assume that the UK has taxing rights and then assess whether any exemptions or easements apply.

When Does the UK Have Taxing Rights Over an Employee’s Income?

To determine whether the UK has the right to tax an employee’s income, we look at the double tax treaty between the UK and the employee’s home country. Most treaties follow the OECD model and apply the same test:

The UK will have taxing rights unless all three of the following conditions are met:

  1. Presence Test: The employee is not present in the UK for more than 183 days in any 12-month period beginning or ending in the relevant tax year.
  2. Employer Test: The remuneration is not paid by, or on behalf of, a UK resident employer. If the employee’s costs are recharged to the UK PE, HMRC may treat the UK entity as the economic employer, even if the legal employer remains overseas.
  3. PE Test: The employee is not working for, or their costs are not borne by, a UK permanent establishment of the employer group.

Where an employee is working on a UK construction or installation project that gives rise to a PE, the third condition above will not be met, and the UK will always have taxing rights. Even if the employee is in the UK for fewer than 183 days, their income relating to UK workdays will be taxable in the UK.

We can help you review your project and assess whether a PE has arisen and advise on the implications for the employee income tax position.

What to Do If Your Project Has Only Recently Become a PE

In many cases, a project may not have been expected to last more than 12 months. As a result, the business may not have considered PE risks or the need to operate UK tax compliance for assignees.

We help clients:

  1. Assess when the PE began for tax purposes
  2. Rectify historic non-compliance
  3. Work with overseas tax advisors to ensure a coordinated approach
  4. Liaise with HMRC where voluntary disclosure is appropriate

If you’re realising now that you should have been meeting UK obligations for your project workers, we can help you get back on track.

First Step: Immigration Compliance

Before considering tax, the first issue is ensuring the employee has the Right to Work in the UK. Since Brexit, EU workers need a visa — and you must confirm this with an immigration advisor. We can signpost trusted specialists if needed.

Managing the UK Tax Position

Depending on whether your business has a PAYE presence in the UK, there are two main approaches:

PAYE stands for Pay As You Earn. It’s the UK’s system for collecting income tax and National Insurance Contributions (NICs) from employees’ wages. Under PAYE, tax and NICs are deducted by the employer at source and paid to HMRC each month.

1. No PAYE Presence

If the project does not involve a rented UK office, and no formal branch or office exists, you likely have no PAYE obligation. Instead, you can:

  • Report UK taxable income via annual Self-Assessment tax returns for each employee
  • Avoid the administrative burden of operating UK payroll

2. With PAYE Presence / Tax Equalised Employees

If there is a PAYE presence, or if your assignees are tax equalised, it may be better to operate a shadow payroll or even a Modified Payroll under EP Appendix 6.

Tax equalisation is an arrangement where the employee receives a guaranteed net income, and the employer covers the UK (and home country) tax liabilities. The employee pays a hypothetical tax amount, equivalent to what they would have paid had they remained in their home country. The employer pays the actual tax due in the UK and retains any tax refunds. More about tax equalisation ›

Modified payroll allows:

  • Gross-up of net guaranteed salary
  • Reporting and tax payments to HMRC on an estimated basis
  • Recovery of tax refunds directly by the employer
  • Extended deadlines for reporting benefits
  • No personal payments on account for employees

Social Security

The UK has agreements with the EU and other countries ensuring that employees pay social security in only one country. For most EU employees, this means obtaining an A1 certificate from the home country.

Our Services

We work closely with overseas HQs and UK-based project leaders to:

  • Review when a UK PE has arisen
  • Assess whether UK taxing rights exist
  • Establish a UK tax compliance plan for your inbound employees
  • Operate shadow or modified payrolls
  • Manage year-end UK tax returns for assignees
  • Rectify past periods if PE status has only recently been identified

FAQs

If the project is a UK PE, the UK can still tax income from day one, even if the employee is in the UK for less than 183 days.

Yes, unless they are a British or Irish citizen. We can refer you to an immigration specialist.

Yes, in some cases — particularly if you do not have a UK PAYE presence. We’ll advise based on your exact setup.

A system allowing employers to gross up income and report/pay taxes on behalf of tax-equalised employees in a streamlined way.

Yes. We can help fix historical non-compliance and agree a remediation plan with HMRC.

Contact Out Experts

Get in touch to ensure your construction or installation project meets UK tax obligations from day one. If your project is already underway, we can still help you get compliant and avoid penalties.

Sarah English

Senior Manager

Liam Perry

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