Guide
CIS registration does not determine employment status
Why being CIS-registered does not make someone self-employed. Understand the critical distinction between CIS (a tax collection mechanism) and employment status (a legal relationship). Covers employment status tests, the CEST tool, IR35 implications, and the risks of misclassification for both contractors and workers.
One of the most common and costly mistakes in construction is assuming that because someone is CIS-registered, they are automatically self-employed. This is wrong. CIS registration and employment status are completely separate legal concepts.
Getting this wrong can result in:
- For contractors: National Insurance demands, penalties, tribunal claims, and back-payment of employee rights
- For workers: Loss of employment protections and benefits you should have had
This guide explains the distinction and helps you avoid these costly errors.
What CIS actually does
The Construction Industry Scheme is purely a tax collection mechanism. It requires contractors to deduct tax from payments to subcontractors and send it to HMRC. That is all it does.
The employment status tests
Employment status is determined by how the working relationship actually operates, not by what the parties call it or which tax scheme applies. Courts and tribunals look at multiple factors:
Key indicators of self-employment (genuine business)
- Substitution: Can send a replacement without the contractor's approval
- Financial risk: Bears risk of loss on contracts (fixed price, own insurance)
- Equipment: Provides significant tools, equipment, or materials
- Control: Decides how, when, and where to do the work
- Multiple clients: Works for several contractors, not just one
- Business structure: Has business premises, marketing, own staff
Key indicators of employment (disguised employee)
- Control: Contractor dictates working hours, methods, and location
- Mutuality: Ongoing obligation to offer work and accept it
- Integration: Works alongside employees, same supervision
- Exclusivity: Works only or mainly for one contractor
- Equipment: Uses contractor's tools and equipment
- Payment: Regular weekly or monthly payments regardless of output
Using the CEST tool
HMRC provides the Check Employment Status for Tax (CEST) tool to help determine employment status. While not legally binding, HMRC will stand by the result if:
- You enter accurate and complete information
- It reflects the actual working arrangement (not just what the contract says)
- The arrangement does not change after the assessment
Best practice: Complete CEST for each engagement and keep the result on file. If challenged, this demonstrates you took reasonable care to determine status correctly.
Check employment status for tax (CEST)
Risks of misclassification for contractors
If HMRC or an employment tribunal determines that a CIS-registered worker was actually an employee, the contractor faces serious consequences:
Tax and National Insurance
- Employer NI: 13.8% on all earnings above the threshold - backdated up to 6 years
- Employee NI: May need to pay the employee's share if not recoverable
- Interest: On all late-paid tax and NI
- Penalties: Up to 100% of the tax due for careless or deliberate errors
Employment rights claims
- Holiday pay: 5.6 weeks per year, potentially years of unpaid entitlement
- Minimum wage: If effective hourly rate was below NMW after recalculation
- Sick pay: Statutory Sick Pay if they were off sick
- Unfair dismissal: If worked 2+ years and terminated
- Redundancy pay: If work ended and they had 2+ years service
- Pension auto-enrolment: Employer contributions should have been made
Total exposure example: A worker misclassified for 3 years on 40,000 pounds annual payments could result in: 16,500 pounds employer NI + 6,700 pounds holiday pay + pension contributions + interest + penalties. Total exposure could exceed 30,000 pounds per worker.
Risks for workers
Workers also face risks if they accept CIS treatment when they should be employees:
- No Statutory Sick Pay when ill
- No holiday pay - must fund own time off
- No redundancy if work ends
- No unfair dismissal protection
- No employer pension contributions
- Personal liability for Class 2 and Class 4 NI instead of employee Class 1
IR35 and CIS - when both apply
The off-payroll working rules (IR35) apply when a worker provides services through their own limited company. In construction, both IR35 and CIS can apply:
- Medium and large contractors must assess employment status under IR35
- If the engagement is "inside IR35" (deemed employment), PAYE must be operated
- CIS may still apply to the labour element of payments to the limited company
- Small company exemption: If you meet 2 of 3 thresholds (turnover under 10.2 million pounds, assets under 5.1 million pounds, under 50 employees), the contractor determines their own status
Understanding off-payroll working (IR35)
Best practice for contractors
To protect your business from misclassification claims:
- Assess each engagement individually - do not assume CIS registration means self-employment. Status depends on how the relationship actually works.
- Use the CEST tool - document your determination for each worker and keep the result on file.
- Review contracts against reality - a contract saying "self-employed" means nothing if the actual working practices indicate employment.
- Monitor for changes - status can change if working practices change. An arrangement that starts as self-employment can become employment over time.
- Keep detailed records - document why you treated someone as self-employed, including evidence of their other clients, equipment, and risk-bearing.
- Take professional advice - for borderline cases, get specialist employment status advice before starting the engagement.
When to use PAYE instead of CIS
If your assessment indicates the worker is actually an employee, you must:
- Register as an employer with HMRC (if not already)
- Put the worker on PAYE payroll
- Deduct Income Tax and employee NI
- Pay employer NI
- Enrol them in your workplace pension
- Provide employment rights (contracts, holiday, sick pay, etc.)
Do not use CIS for someone who should be on PAYE. The penalties for wrong classification are far higher than the administrative cost of doing it correctly.
Common scenarios
Scenario 1: The regular labourer
Situation: A labourer works for you every week, uses your tools, works your hours, and has done so for 2 years.
Assessment: Almost certainly an employee. The regularity, control, and integration all point to employment. CIS treatment is incorrect - use PAYE.
Scenario 2: The specialist subcontractor
Situation: An electrician does a job for you. They have their own van, tools, insurance, work for multiple contractors, and quote fixed prices.
Assessment: Likely genuinely self-employed. CIS treatment is correct.
Scenario 3: The one-man band on long contract
Situation: A sole trader plasterer works on your site 5 days a week for 6 months. They use their own tools but work your hours and take direction from your foreman.
Assessment: Borderline. Use CEST tool and document carefully. The control and integration suggest employment despite having own tools.
Related guides
- Register as a CIS contractor - how to register and your ongoing obligations
- Verify a subcontractor's CIS status - checking verification before payment
- Construction tax compliance overview - how CIS, VAT, CITB, and PAYE work together
- VAT reverse charge for construction - when to apply the reverse charge