Corporation Tax Compliance for UK Construction or Installation Projects
If your business is managing a construction or installation project in the UK that lasts more than 12 months, you may have a UK Permanent Establishment (PE) for corporation tax purposes. This has significant implications, including the need to register for and comply with UK corporation tax obligations.
We work with overseas clients operating across a wide range of project types:
- Renewable energy installations (e.g. wind, solar, hydro, biomass, biogas)
- Power generation (e.g. nuclear, combined heat & power)
- Major manufacturing or industrial installations
- High-voltage or electrical infrastructure
- Commissioning of machinery or production lines
Many of these projects begin with short-term intentions but evolve over time. If your UK site activities now exceed 12 months, you will likely be considered to have a UK PE, triggering UK corporation tax obligations.
Understanding When a UK PE Arises
The UK’s domestic tax legislation defines a permanent establishment to include:
- An installation or structure for the exploration of natural resources
- A mine, oil or gas well, quarry, or any other place of extraction
- A building site or construction or installation project
Domestic legislation does not include a duration test. However, under most double tax treaties, a construction PE is deemed to exist only if the project lasts more than 12 months.
The 12-month clock starts when any physical work begins on site, whether by your employees or a subcontractor. Temporary interruptions (e.g. weather delays, waiting for materials) do not pause the clock.
We can help you determine:
- Whether your UK activities constitute a PE under domestic and treaty law
- When your UK PE began (and when it may end)
What to Do When a PE Exists
Once you’ve identified a UK PE, you’ll need to:
- Register for UK corporation tax
- Prepare and file a UK corporation tax return each year
- Pay UK corporation tax by the deadline
We guide you through every step.
Many businesses worry about the UK’s unusual tax year for individuals (ending 5 April). The good news is that corporation tax uses normal accounting periods (i.e your usual year-end date), and is not affected by this.
To learn more about UK corporation tax filing deadlines, visit our Corporation Tax Filing & Payment Deadlines page.
Do You Need to Register a UK Branch?
Often, clients ask whether a branch must be registered at Companies House. For a UK PE arising solely from a construction project, the answer is usually no. Companies House is not a “trading register” like in other countries.
See our guide on When to Register a UK Branch for further details
How Are Profits Calculated?
The profits attributable to a UK PE are based on the separate enterprise principle — treating the PE as if it were a standalone entity:
- The PE is assumed to have the same credit rating as the head office
- It is assumed to have reasonable equity and loan capital as if it were a separate entity
This prevents thin capitalisation — interest and financing costs must be at arm’s length. HMRC expects profit attribution to be justified based on facts and supported by documentation.
What Expenses Are Deductible?
You can deduct executive and general administrative expenses incurred anywhere in the world — as long as they relate to the PE. The deduction is allowed for the actual cost to the non-resident company.
We’ll help you determine which costs are deductible and how to account for them correctly.
Transfer Pricing and Documentation
Transfer pricing documentation is usually prepared at group level and should include:
- Functional analysis of risks between head office and the UK PE
- Choice of profit attribution method
The UK has no prescribed method — any appropriate OECD-aligned method is acceptable. The UK tax authorities require contemporaneous documentation.
We can advise whether your selected method is suitable from a UK standpoint.
Don’t Forget Employee Tax Compliance
If your project gives rise to a UK PE, the UK will also have taxing rights over the income of any employees working on the UK project — even if they are here for fewer than 183 days.
You must consider:
- Whether income tax is due in the UK for the assignees
- Whether a UK payroll is needed
- Whether year-end UK tax returns are required for the employees
Visit our guide on Taxation of Employees Working on a UK PE Project to understand what to do and how we can help.
Our Services
We support overseas businesses with:
Determining whether and when a UK PE arises
Registering for UK corporation tax
Preparing UK corporate tax returns
Advising on allowable deductions and capital attribution
Reviewing or preparing transfer pricing documentation
Advising on whether Companies House branch registration is needed
Rectifying historical non-compliance if a PE has only recently been identified
FAQs
From the first physical work on the UK site — even by subcontractors. Temporary delays don’t reset or pause the clock.
No. A construction PE usually doesn’t trigger a Companies House registration.
Yes. If a PE exists, you must file even if the UK project breaks even or runs at a loss.
Use the separate enterprise principle. We’ll help you choose an appropriate method based on your project setup.
We’ll help you backdate the registration, file historical returns, and liaise with HMRC to minimise penalties.
Contact Our Experts
Get in touch to confirm your UK PE position and meet your UK tax obligations correctly. Whether you’re just getting started or need to fix past compliance, we’re here to help.
Sarah English
Senior Manager
Head of Direct Taxes
Callum Davis
Associate
Corporate Income Taxes, Personal Tax & VAT
Common Tax Mistakes Overseas Contractors Make
Understanding these risks early can help you avoid costly disruptions to your project.