Alex is Sprintlaw’s co-founder and principal lawyer. Alex previously worked at a top-tier firm as a lawyer specialising in technology and media contracts, and founded a digital agency which he sold in 2015.
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If you engage contractors in the UK, you can’t ignore IR35 and the off‑payroll working rules. Since the 2021 private sector reforms, many businesses must assess a contractor’s tax status and issue a Status Determination Statement (SDS) with “reasonable care”.
Get this wrong and you could be liable for PAYE, NICs, interest and penalties. Get it right and you’ll reduce risk, set expectations clearly with your suppliers and keep projects moving without last‑minute tax surprises.
In this guide, we explain when an SDS is required, what it must include, a step‑by‑step assessment process, and a plain‑English Status Determination Statement template you can adapt for your business.
What Is A Status Determination Statement (SDS) And When Do You Need One?
An SDS is a written statement that tells a contractor and (where relevant) the agency in the supply chain whether the engagement is “inside IR35” (deemed employment for tax) or “outside IR35” (genuine self‑employment for tax) - and the reasons for that conclusion.
The duty to issue an SDS sits within the off‑payroll working rules in Chapter 10, Part 2 of the Income Tax (Earnings and Pensions) Act 2003 (ITEPA), commonly called IR35. In the private sector, since April 2021:
- Medium and large businesses are responsible for determining status and issuing an SDS before the contract starts (or before the first payment).
- Small businesses are generally exempt - the contractor’s PSC (personal service company) determines status and accounts for tax.
For companies, the small company exemption usually follows the Companies Act thresholds (meeting at least two of the following: ≤50 employees, turnover ≤ £10.2m, balance sheet total ≤ £5.1m). Groups and connected companies require special attention - if you’re unsure about size or group status, get tailored advice.
Even if you’re exempt, making a thoughtful status assessment is still good practice. It informs how you draft your contracts and manage day‑to‑day operations, and it can be relevant if your size changes in future.
Status Determination Statement Template (Copy, Paste And Tailor)
Here’s a practical Status Determination Statement template you can adapt. It’s designed for UK businesses engaging contractors through an intermediary (for example, a PSC). Replace bracketed text with your details and tailor the reasons to your engagement. Remember: avoid generic boilerplate - your SDS should reflect the real‑world working practices.
Plain‑English SDS Template
Status Determination Statement (SDS) Off‑Payroll Working (IR35) Client (End User): Engagement/Role: Supplier/Intermediary: Contractor/Worker: Start Date: Assessment Date: Assessor: Status Determination: Summary Of Reasons: 1) Personal service and substitution: 2) Control and supervision: 3) Mutuality of obligation: 4) Equipment, financial risk and integration: 5) Actual working practices: Additional Considerations: Disagreement Process (Client-Led): If you disagree with this determination, please email with reasons within days. We will consider your representations and provide a reasoned response within 45 days in line with the off-payroll rules. Distribution: This SDS has been provided to: - The Contractor/Worker: - The Intermediary/Agency: - Internal Records: Signed:
Use this as a starting point. The strongest SDS documents pair clear reasoning with contracts and working practices that actually support the status in real life.
How To Make A Compliant SDS: Process, Reasonable Care And Evidence
The law requires you to take “reasonable care” when making an SDS. In plain terms, that means using a structured process, gathering evidence, and avoiding copy‑paste determinations. Here’s a practical workflow.
1) Gather The Facts
- Scope and outputs - what is being delivered, by when, and to what standard?
- Working practices - where, when and how will the work be done; who directs it; how embedded is the role?
- Commercial terms - pricing model (fixed price vs day rate), substitution rights, insurances, equipment, ability to subcontract or hire assistants.
- Supply chain - are there agencies; who pays whom; do you control interview/selection?
Don’t guess. Speak with the project lead who will manage the engagement and align on how things will work in practice. If your approach is “we’ll decide later”, that’s a red flag for reasonable care.
2) Assess Employment Status Factors
Focus on the established status factors, not a single headline point. A holistic assessment should consider personal service (and substitution), control, mutuality of obligation, financial risk, and whether the individual is “in business on their own account”. For a deeper refresher on these tests, see employment status tests.
3) Align Contracts With Reality
An SDS is only as strong as the contract and day‑to‑day practices that sit behind it. If you’re engaging a genuine contractor, have a robust Contractors Agreement or a Consulting Agreement that reflects actual substitution rights, deliverables, payment terms and risk allocation. If the role is inside IR35 and you need an employee, use a compliant Employment Contract instead.
4) Document Your Reasoning
Write the SDS reasons in clear, specific language. Reference the evidence you relied on (e.g., substitution clause plus prior substitution used on similar projects; fixed‑price statement of work; contractor‑provided equipment). Generic wording like “we considered all factors” won’t cut it.
5) Communicate And Keep Records
- Provide the SDS to the contractor and the next entity in the chain (e.g., the agency) before work starts.
- Set up a client‑led disagreement process and respond within 45 days if challenged.
- Retain your assessment notes, SDS and signed contracts in a central record.
Taking these steps demonstrates reasonable care and puts you in a stronger position if HMRC ever asks questions.
Inside IR35 vs Outside IR35: What The Factors Usually Look Like
No single factor is decisive, but patterns do emerge. Here’s how the key factors typically present.
Personal Service And Substitution
- Outside IR35: A genuine, practical right to provide a substitute at the contractor’s cost, with only basic vetting for skills and security.
- Inside IR35: The specific individual is required; substitution is theoretical, heavily restricted, or practically impossible.
Control And Supervision
- Outside IR35: Control is over “what” is delivered, not “how”. The contractor decides methods, hours and often location to meet outcomes.
- Inside IR35: You direct day‑to‑day tasks, hours, location and methods, akin to an employee relationship.
Mutuality Of Obligation (MOO)
- Outside IR35: No obligation for ongoing work beyond the project; renewals require fresh agreement.
- Inside IR35: Expectation of continuous work with an obligation to offer and accept tasks.
Financial Risk And “In Business On Own Account”
- Outside IR35: Fixed‑price or milestone billing, possibility of loss, own equipment and insurance, ability to send assistants, multiple clients.
- Inside IR35: Paid by time worked, no material financial risk, integrated tools and benefits, exclusivity to you.
The best way to manage these factors is to design the engagement deliberately. If you truly need contractor flexibility and independence, build that into your contract, commercial model and working practices from day one. If you actually need a managed resource under your control, treat them as an employee and use the right documentation.
How To Handle Disagreements, Agencies And Overseas Contractors
You must operate a client‑led disagreement process. If the contractor or agency disputes your SDS, acknowledge receipt, review their reasons and respond with a revised SDS or a confirmation of your decision within 45 days. Failing to respond can shift tax liability to you.
In supply chains, issue the SDS to the worker and the next party (often the agency). If you don’t take reasonable care or you don’t pass the SDS down appropriately, liability can move up the chain to you as the end client.
If any part of your supply chain is overseas, pay close attention. Off‑payroll rules can still bite where the client is UK‑based, and tax withholding obligations may fall on the “fee‑payer”. If you’re sourcing talent abroad, consider how your IR35 analysis interacts with local employment law and tax. Where that’s relevant, it’s worth revisiting your approach to engaging overseas contractors.
Where you need to flex resources between group entities or clients, a Secondment Agreement can set the right legal framework - separate from IR35, but useful for clarifying who directs and pays whom.
Contracts And Practicalities That Support Your SDS
Your SDS should never exist in a vacuum. Make sure your documents and daily practices tell the same story.
- Use the correct agreement for the relationship. For genuine contractors, adopt a tailored Contractors Agreement that backs up substitution, independence and outcome‑based delivery.
- Scope and pricing matter. A statement of work with clear deliverables and milestone or fixed‑price billing supports an outside IR35 position.
- Avoid employee‑style integration. Limit access to employee benefits, avoid line management duties and keep the contractor outside your internal hierarchy.
- Plan exit terms. Even with contractors, it’s smart to set clear termination provisions and notice arrangements - see practical points around contractor notice periods.
- Be careful with downstream delivery. If a contractor wants to sub‑out work, clarify responsibilities and quality controls; where relevant, think about the differences in a contractor vs subcontractor setup.
If you decide the role is inside IR35 (or you really need ongoing control and integration), shift to an employee relationship with an Employment Contract and handle PAYE/NICs normally.
Common Mistakes (And How To Avoid Them)
- Copy‑pasting generic SDS wording. HMRC expects “reasonable care”, which means specific reasons linked to your engagement. Use the template as a framework, not a shield.
- Letting contracts and reality drift apart. If managers direct daily how/where work is done, a paper right of substitution won’t save an outside IR35 decision.
- Issuing the SDS too late. The SDS should be in place before the engagement starts or before the first payment. Don’t wait until month two.
- Ignoring the disagreement process. If someone challenges your SDS, you must respond within 45 days. Silence can transfer liability to you.
- Missing the small business threshold change. If your business grows, the exemption can fall away. Review your status annually and plan ahead.
- Relying only on tools. HMRC’s CEST tool and third‑party questionnaires can help, but you still need to sense‑check outputs and document your own reasoning.
- Overlooking global hires. If you’re bringing in talent from abroad, align your IR35 approach with how you’re engaging overseas contractors and where tax is withheld.
- Using the wrong document type. If it walks and talks like employment, don’t try to force it into a contractor model - use an Employment Contract and manage risk properly.
Step-By-Step: Completing Your SDS With Confidence
Step 1: Define The Engagement
Write a short scope: deliverables, timeline, location, tools, who signs off. Clarify whether you need “hands on keys” resourcing or an outcome‑based project.
Step 2: Select The Right Engagement Model
Decide whether you need an employee or a genuine contractor. If it’s a contractor, prepare a fit‑for‑purpose Contractors Agreement and statement of work. If it’s actually a role under your control, use an employee arrangement.
Step 3: Assess Status (Reasonable Care)
Work through personal service, control, mutuality, financial risk and integration. Cross‑check your conclusions against the factors in the worker vs employee distinction and wider status guidance.
Step 4: Draft The SDS
Populate the template with your decision and concrete reasons. Keep it specific and plain‑English. Include a clear disagreement route and who to contact.
Step 5: Communicate And File
Send the SDS to the contractor and the next party in the chain (e.g., the agency), store it centrally, and calendar a review date for longer engagements.
Step 6: Monitor Working Practices
Check in after onboarding. If practices drift (for example, day‑to‑day control increases), either correct the working approach or reassess status. If the engagement evolves into managed resourcing, consider switching to an employee model or adjusting the scope. Where a contractor is bringing in additional help, make sure you’re comfortable with the contractor vs subcontractor split and liabilities.
Key Takeaways
- An SDS is mandatory for medium and large private‑sector clients under IR35 - issue it before work starts and take “reasonable care”.
- Use a clear, tailored Status Determination Statement template that records your decision and the specific reasons behind it.
- Align contract terms and real‑world practices; if it’s truly a contractor engagement, use a robust Contractors Agreement or Consulting Agreement. If it’s employment in practice, use an Employment Contract.
- Operate a client‑led disagreement process and respond within 45 days to challenges from contractors or agencies.
- Keep records of your assessment, SDS and contracts - they’re your evidence of reasonable care if HMRC reviews your decision.
- Reassess if your business size changes, the engagement evolves, or working practices start to look more like employment.
If you’d like help putting together a compliant SDS, aligning your contracts, or sense‑checking a tricky engagement, you can reach us on 08081347754 or team@sprintlaw.co.uk for a free, no‑obligations chat.
