Outside IR35 Contractors: Complete Legal Guide 2024

Aspect Inside IR35 Outside IR35 Tax Status Treated as employee for tax Genuine self-employed business Hiring Company Liability Full PAYE responsibility Contractor handles own taxes Contract Type Weekly timesheets, daily rates B2B service agreement, SOW Control Company manages schedule & tools Contractor controls delivery IP Ownership Typically company-owned Often contractor-owned (assignable) Risk & Liability Company assumes all risk Contractor carries insurance Cost to Hiring Company £60-80k + 20% overheads £50-70k total cost

Key IR35 Rules for 2024

• Off-Payroll Working Rules: If you're hiring a contractor via an intermediary (agency, limited company), you must assess their IR35 status and deduct PAYE if inside IR35.
• The Substitution Test: Can the contractor send someone else to do the work? If no, they're likely inside IR35.
• Mutuality of Obligation: Is there an ongoing obligation to provide work or to accept it? If yes, inside IR35.
• Control: Who controls how, when, and where the work is done? More control = inside IR35.
• Integration: Are they integrated into your team like an employee? Inside IR35.
• Personal Service: Must the same person perform the work? Inside IR35.

How to Hire Contractors Outside IR35 (4-Step Process)

Step 1: Structure the Engagement as a B2B Service Contract

The contractor must be operating as a genuine business (limited company or sole trader with clients). Have a formal contract that states:

• Fixed deliverables or defined output (not hourly timesheets)
• Contractor invoices for services rendered
• Clear start and end dates or project milestones
• Contractor can substitute another person (if they choose)
• Contractor invoices monthly and is paid by company

Step 2: Use a Statement of Work (SOW)

A Statement of Work is the gold standard for outside IR35 hiring. It includes:

• Scope of work and deliverables
• Timeline and milestones
• Payment schedule (fixed price or day rate)
• Contractor responsibilities and timelines
• IP assignment clause (if needed)
• Contractor indemnity and insurance requirements

Step 3: Avoid Employee-Like Conditions

Do NOT:

• Require them to work 9-5 Monday-Friday
• Ask for daily timesheets or hourly logs
• Provide company equipment or integrate them into your office
• Require them to attend all internal meetings
• Prevent them from working for other clients
• Treat them as part of your payroll team

Step 4: Get an IR35 Assessment Document

Have your contractor or their accountant provide:

• A formal IR35 status declaration
• Evidence they're operating as a genuine business (company registration, insurance, other clients)
• Their professional indemnity insurance certificate

Outside IR35 Engagement Models That Work

1. Fixed-Price Statement of Work (SOW)

Best for: MVPs, integrations, defined projects
Budget certainty: ✅ Full certainty
IR35 Status: ✅ Easily defensible as outside IR35

Example: "Deliver a REST API for our e-commerce platform by June 15, for £25,000. Full IP assigned to us."

2. Time & Materials with Deliverables

Best for: Product development, evolving scope
Budget certainty: ⚠️ Limited visibility
IR35 Status: ✅ Outside IR35 if capped and milestone-driven

Example: "Day rate £600, capped at 100 days. Deliver 2 features per sprint."

3. Dedicated Contractor (Part-Time / Full-Time)

Best for: Long-term team extension, maintenance
Budget certainty: ✅ Predictable
IR35 Status: ✅ Outside IR35 via B2B contract with flexibility

Example: "3 days per week React developer for 6 months, flexible schedule, £4,000/week."

Outside IR35 Compliance Checklist

Real Costs: Outside IR35 vs Permanent Hire

Here's what you actually pay:

Cost Factor	Full-Time Employee	Outside IR35 Contractor (6 months)
Base Salary	£60,000	£60,000
Employer NI (15%)	£9,000	£0
Pension (3%)	£1,800	£0
Holiday Pay (5.6 weeks)	£6,461	Built into day rate
Onboarding / Training	£2,000	£0
Equipment	£2,000	£0
Total Annual Cost	£81,261	£60,000

Savings: 26% with an outside IR35 contractor — and you can scale up/down as needed.

FAQs

Can I hire an individual as outside IR35?

Only if they operate as a sole trader with their own business (company registration, business insurance, multiple clients). Hiring an individual who only works for you is almost certainly inside IR35.

What if the contractor is inside IR35?

You must deduct PAYE tax and National Insurance from their payments. You become responsible for their employment tax — exactly as if they were on payroll. You can still hire them, but there's no tax benefit.

Do I need an accountant to assess IR35?

It's highly recommended. IR35 assessments are complex, and getting it wrong can result in back-tax bills and penalties. A professional IR35 assessment (£300-500) is worth the insurance.

Can I hire abroad and avoid IR35?

If the contractor is outside the UK and works remotely, different rules apply. However, if you're controlling them from the UK, HMRC may still assess them as inside IR35. Get tax advice for international hires.

What if I hire through an agency?

Agencies can structure contracts as outside IR35 if they use proper B2B agreements. However, many agencies don't — they take PAYE responsibility themselves. Always ask the agency for their IR35 status documentation before engaging.