What Are the Legal Requirements to Start a Construction

Starting a construction company without understanding your legal obligations is how businesses get into serious trouble. The construction industry is one of the most regulated sectors in the UK – not to create bureaucracy, but because the consequences of getting it wrong (injury, structural failure, financial dispute) are serious.

Here’s a comprehensive overview of the legal requirements, structured in order of priority.

1. Business Registration

Sole trader: Register with HMRC for Self Assessment by 5 October of the tax year after you start trading. Free. Required by law.

Limited company: Register at Companies House. £50 online. Requires a registered address, director details, and Articles of Association. Register for Corporation Tax within 3 months of starting to trade.

Both structures require keeping accounting records for at least 5 years (sole trader) or 6 years (limited company) and filing annual tax returns.

2. Tax Obligations

Income Tax / Corporation Tax – pay tax on profits. Sole traders via Self Assessment; limited companies via Corporation Tax return.

VAT – register when taxable turnover exceeds £90,000 in a 12-month period. Voluntary registration is possible below this threshold.

CIS (Construction Industry Scheme) – if you pay subcontractors, you must register as a CIS contractor, verify subcontractors, make appropriate deductions, and submit monthly CIS returns to HMRC. Failure to operate CIS correctly results in penalties.

PAYE – if you employ anyone, you must register as an employer and operate PAYE, deducting income tax and National Insurance from wages and paying employer’s NI.

3. Insurance Requirements

Employers Liability Insurance – legally required under the Employers Liability (Compulsory Insurance) Act 1969. Must be in place before you employ anyone (including labour-only subcontractors in many circumstances). Minimum £5m cover. You must display the certificate at your workplace.

Public Liability Insurance – not legally required by statute, but practically essential. Most clients and all commercial contracts require it. Minimum £2m, typically £5-10m for commercial work.

Motor Insurance – vehicles used for business purposes must be covered for business use. A standard personal policy does not cover commercial use.

4. Health & Safety Obligations

Construction is the most heavily regulated sector for health and safety in the UK. Your key obligations:

Health and Safety at Work Act 1974 – creates a general duty of care to employees, subcontractors and the public. Breaches can result in criminal prosecution and unlimited fines.

CDM Regulations 2015 (Construction Design and Management) – apply to virtually all construction projects. Key duties vary by role: – Client – appoints Principal Designer and Principal Contractor on notifiable projects – Principal Contractor – overall responsibility for site health and safety – Contractor – responsibility for their own workers and activities

Risk Assessments and Method Statements (RAMS) – required for any significant work activity. Must be written, communicated to workers, and reviewed when circumstances change.

Notifiable projects – projects lasting more than 30 working days with more than 20 simultaneous workers, or exceeding 500 person-days, must be notified to the HSE (F10 notification).

5. Planning and Building Regulations

Planning permission – required for new builds, extensions above permitted development limits, and change of use. Applied for by the property owner/developer, not the contractor – but you should not start work without confirming it’s been obtained.

Building Regulations – set minimum standards for construction work in England and Wales. Most construction work requires Building Regulations approval via building control. Some work can be self-certified under competent person schemes.

Party Wall Act – work affecting a party wall, boundary wall or excavation near a neighbouring building requires proper party wall notices.

6. Employment Law (If You Take On Staff)

Written contracts of employment – required by law from day one of employment.

National Living Wage – must pay at least the NLW (£12.21/hr for workers 21+ from April 2025) to all employees.

Holiday entitlement – 5.6 weeks per year for full-time employees.

Pension auto-enrolment – required if you employ anyone aged 22+ earning above the auto-enrolment threshold.

Right to Work checks – legally required to check that every employee has the right to work in the UK before they start.

7. Waste and Environmental Obligations

Waste carrier registration – required if you transport construction waste (including to a tip).

Hazardous waste – asbestos, solvents, oils and similar materials have specific disposal requirements.

Environment Act – duties around pollution prevention on site.

Conclusion

Starting your own trades business is one of the most financially and personally rewarding things a skilled tradesperson can do. The foundations – the right structure, the right insurance, the right systems – take a few weeks to set up properly, but getting them right from the start saves significant time and money further down the line. For further guidance, visit HSE: legal duties for employers.

Frequently Asked Questions