Employee or Subcontractor?
UK employment status tests, IR35, CIS, and what misclassification really costs
You cannot simply choose whether someone is an employee or subcontractor — UK law looks at the reality of the working relationship. HMRC uses a multi-factor test covering control, substitution, mutuality of obligation, financial risk, equipment provision and integration. Getting it wrong means backdated PAYE income tax, employer NI at 15%, auto-enrolment pension arrears, interest, and penalties of up to 100% — a £30,000/year 'subcontractor' reclassified over 2–3 years can become a five-figure hit.
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Guidance, not advice. We explain the rules, we don't assess your situation. Always seek financial or tax advice from your accountant, or contact HMRC. Read our editorial scope →
The core question
Employment status in UK law is determined by a combination of statute (ITEPA 2003), case law (Ready Mixed Concrete, Autoclenz, Uber v Aslam), and HMRC guidance. You cannot contract out of it. The label in your agreement — 'self-employed', 'subcontractor', 'consultant' — is the starting point, not the endpoint. HMRC and the courts look at the actual working practices.
HMRC employment status tests
HMRC uses a multi-factor test. No single factor is decisive; the courts weigh them together. Below are the six main factors with employee-type vs self-employed-type indicators.
1. Control
Employee-type: the engager dictates what work is done, how, when, and where. The worker has no discretion over methods. Self-employed-type: the worker decides how to achieve the result, sets their own hours, and controls the manner of working. The engager only specifies the outcome.
2. Substitution (genuine right = strongest SE indicator)
Employee-type: the worker must personally perform the work. No right to send a substitute. Self-employed-type: the worker has an unfettered right to send a substitute, and has done so in practice. This is the single strongest indicator of self-employment. A 'conditional' right (e.g. substitute must be approved) weakens the indicator but does not eliminate it.
3. Mutuality of obligation
Employee-type: the engager is obliged to offer work and the worker is obliged to accept it. Ongoing expectation of work. Self-employed-type: no ongoing obligation. Each contract is separate. The worker can turn work down without penalty and work for others simultaneously.
4. Financial risk
Employee-type: the worker is paid regardless of profit or loss. No risk of non-payment if the job is done. Expenses are reimbursed. Self-employed-type: the worker risks their own capital, quotes fixed prices, bears the cost of rectifying mistakes, and is not paid if the work fails.
5. Equipment
Employee-type: the engager provides all tools, materials, and equipment. Self-employed-type: the worker provides their own significant equipment (van, specialist tools, computer). Note: minor equipment (uniform, basic hand tools) does not indicate self-employment.
6. Integration
Employee-type: the worker is part of the business organisation — on the org chart, attending team meetings, wearing uniform, using internal systems. Self-employed-type: the worker operates as an independent business, with their own branding, website, insurance, and multiple clients.
CEST tool
The Check Employment Status for Tax (CEST) tool on gov.uk is HMRC's free online questionnaire. It asks about control, substitution, and financial risk. HMRC says it will stand by an honest result. Key caveats: • CEST does not properly test mutuality of obligation (MOO). • It can return 'unable to determine' for borderline cases. • You must answer based on actual practice, not the written contract. • Always save the PDF output with timestamp. CEST is a useful first screen for straightforward arrangements. For complex, high-value, or borderline cases, get specialist advice.
Consequences of misclassification
If HMRC reclassifies a 'subcontractor' as an employee, the engager becomes liable for: • Backdated PAYE income tax (20%/40%/45% depending on earnings) • Backdated employer National Insurance (~15% from April 2025, on earnings above £5,000) • Backdated employee National Insurance (deducted from the worker, but if not deducted, the employer pays) • Interest on underpaid tax from the original due date • Penalties: 0% for reasonable care, 30% for careless, 70% for deliberate, 100% for deliberate and concealed • Auto-enrolment pension arrears (3% employer minimum, plus backdating) Time limits: 4 years for normal assessments, 6 years for careless errors, 20 years for deliberate concealment (TMA 1970).
IR35 and off-payroll working
IR35 (ITEPA 2003) prevents disguised employment through limited companies. Two chapters apply: Chapter 8 (small clients): the worker decides whether they are inside or outside IR35. If inside, they pay themselves a deemed salary through their PSC. Chapter 10 (medium/large clients): the client decides status and issues a Status Determination Statement (SDS). The client is liable for getting it wrong. The SDS must be passed down the labour supply chain. Inside IR35: the worker is treated as a deemed employee. The Ltd company pays employer NI, and the worker pays income tax and employee NI on the deemed salary. The tax advantage of dividend extraction disappears. Outside IR35: normal Ltd company rules apply — optimal salary + dividends.
CIS
The Construction Industry Scheme (FA 2004 + SI 2005/2045) applies to construction work in the UK. Contractors must verify subcontractors with HMRC and deduct tax at source: • 20% deduction: subcontractor registered with HMRC under CIS • 30% deduction: subcontractor not registered • 0% deduction: subcontractor has gross payment status (passes turnover, business, and compliance tests) Monthly CIS returns are due by the 19th of each month. Late filing penalties: £100 (1 day late), £200 (2 months late), then £300 or 5% of CIS deductions (whichever is higher) at 6 and 12 months. Critical: CIS registration does NOT determine employment status. A CIS-registered subcontractor can still be an employee for PAYE and employment law purposes if the reality of the relationship points to employment.
Auto-enrolment from employee #1
The Pensions Act 2008 requires every employer to automatically enrol qualifying workers into a pension scheme. There is no 'wait until 5 staff' threshold — the duty applies from employee #1. Qualifying worker: aged 22–State Pension Age, earning over £10,000/year, ordinarily working in the UK. Minimum contributions: 8% total of qualifying earnings (£6,240–£50,270 band), of which at least 3% must come from the employer. The worker pays the remaining 5% (often via salary sacrifice). The Pensions Regulator can fine employers £400 fixed penalty plus £50–£10,000 per day for ongoing non-compliance. If you misclassify an employee as a subcontractor, you miss auto-enrolment and become liable for backdated employer contributions plus fines.
Umbrella companies
Umbrella companies employ contractors on a PAYE basis and supply their labour to end clients. The contractor is technically an employee of the umbrella. How it works: the end client pays the umbrella the contract rate. The umbrella deducts employer costs (employer NI, apprenticeship levy), their margin (£15–£30/week), and then runs PAYE on the remainder. The contractor receives a payslip with PAYE tax, employee NI, and pension deductions. Risks: • Disguised remuneration: some umbrellas use loan schemes or artificial arrangements to inflate take-home. HMRC attacks these aggressively. • Supply-chain liability: under Chapter 10 IR35, if the end client issues an SDS saying 'inside IR35', the fee-payer (often the umbrella) is responsible for PAYE compliance. • Holiday pay: umbrellas must fund 5.6 weeks' holiday pay from the contract rate. Some roll it into the hourly rate; check your payslip carefully.
Scenarios
Four common situations showing how the tests apply in practice.
(a) Plumber hiring a mate
You run a plumbing business and need an extra pair of hands for 3 months. The 'mate' uses your van, your tools, follows your instructions, and has no right to send a substitute. Verdict: Almost certainly an employee. You should run PAYE, pay employer NI, and auto-enrol. If you treat them as self-employed, the risk of reclassification is high.
(b) Salon chair renter
A hairdresser rents a chair in your salon for £200/week. They set their own hours, use their own tools, book their own clients, and have their own insurance. They can send a substitute stylist (and have done so when ill). Verdict: Strong self-employment indicators. Chair rental is a well-established model. Risk: if you control their prices, require them to use your booking system exclusively, or prevent them working elsewhere, the balance shifts toward employment.
(c) IT consultant + developer's Ltd (small vs medium/large client)
You are an IT consultant working through your PSC for a client. If the client is small (meets two of: ≤£10.2m turnover, ≤£5.1m balance sheet, ≤50 employees), you decide IR35 status. If medium/large, the client decides and issues an SDS. You work from home, set your own hours, use your own laptop, and have multiple clients. You have a substitution clause and have sent a colleague for one week. Verdict: Likely outside IR35. But if the client requires you to attend daily stand-ups, use their equipment, and forbids substitution, the status shifts toward inside IR35.
(d) Restaurant weekend staff (zero-hours = still employment)
You hire kitchen porters on zero-hours contracts for weekend shifts. They wear your uniform, use your equipment, follow your head chef's instructions, and cannot send substitutes. Verdict: Employees. Zero-hours does not prevent employment status. They are entitled to NMW, holiday pay, pension auto-enrolment (if eligible), and unfair dismissal protection after 2 years. Calling them 'casual subcontractors' does not change this.
Cost comparison at £30k
A direct cost comparison for hiring someone at a £30,000 annual cost to you.
| Cost item | Employee (£30k salary) | Subcontractor (£30k invoice) |
|---|---|---|
| Base pay / invoice | £30,000 | £30,000 |
| Employer NI (15% above £5k) | ~£3,750 | £0 |
| Auto-enrolment pension (3%) | ~£712 | £0 |
| Employer NIC + pension less EA | ~£3,962 | £0 |
| Total cost to engager | ~£33,962 | £30,000 |
| Reclassification risk (2yr) | N/A | £9k–£16k+ |
| Admin burden | Payroll monthly | CIS monthly if construction |
Decision framework
Six steps to get employment status right every time.
- ☐Define the reality: write down what actually happens — hours, location, equipment, control, substitution — not what the contract says.
- ☐Run the status tests: score control, substitution, MOO, financial risk, equipment, and integration honestly.
- ☐Use CEST: run the gov.uk tool based on actual practice, save the PDF.
- ☐Layer CIS/IR35: if construction, check CIS. If through a PSC, check IR35 Chapter 8 or 10.
- ☐Price in the real cost: if employee, budget employer NI + pension + payroll software. If subcontractor, budget reclassification risk insurance.
- ☐Set up infrastructure: employee = payroll, pension, contract of employment. Subcontractor = written agreement, substitution clause, invoice template, own insurance evidence.
Statute references: ITEPA 2003 Part 2 Chapter 8, Chapter 10; FA 2020; SI 2005/2045; Pensions Act 2008; Companies Act 2006 s.382.
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Frequently asked questions
What happens if I miss the Self Assessment deadline?+
Do I need an accountant or can I file Self Assessment myself?+
How do payments on account work?+
Does using CIS prove someone is self-employed?+
What is the CEST tool and should I trust it?+
What is IR35?+
Are zero-hours workers employees?+
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