IR35 advisory UK — understand the engagement, not just the contract.
Britvex helps contractors, personal service companies and UK businesses understand off-payroll working responsibilities, examine the evidence behind an employment-status conclusion and connect the outcome to tax, payroll and company records. Every engagement has its own facts, parties and risks.
IR35 is about the real relationship behind the invoice.
Off-payroll working rules target arrangements in which an individual provides services through an intermediary but would be an employee for tax purposes if engaged directly. They do not ban legitimate contracting or assume that every limited-company worker is an employee.
An individual providing services
A worker may provide services through a personal service company, partnership or another relevant intermediary. The individual’s status is assessed against the end client’s engagement.
The contractor’s company
A personal service company is commonly controlled by the worker. Its accounts, fees, payroll, dividends and tax position may interact with an inside-IR35 determination.
The business receiving the work
The organisation that receives the services may have a duty to determine status, issue a reasoned SDS and handle disagreements, depending on size and sector.
The party paying the intermediary
The deemed employer is generally the qualifying party immediately above the intermediary in the chain. It may be an agency or end client and may need to operate PAYE and NIC.
The answer changes with the client — not merely with the contractor.
In the UK, the statutory distinction between Chapter 8 intermediary rules and Chapter 10 off-payroll rules can determine who makes the status decision and how tax is accounted for. Start with the end client and the full contractual chain.
Chapter 10 normally applies. The public-sector end client is responsible for a reasoned status determination. When the engagement is inside the rules, the deemed employer in the payment chain normally operates relevant deductions and employer charges.
Chapter 10 normally places the status determination and SDS obligations on the end client. An agency or another qualifying fee-payer may be the deemed employer. Size must be tested under the applicable tax-year rules and group provisions.
The end client is generally not responsible for Chapter 10 SDS decisions. The worker’s intermediary must consider Chapter 8 rules for the engagement. Small-client treatment is not an automatic outside-IR35 finding.
Where the client has no relevant UK connection under the statutory test, Chapter 10 normally does not apply. Chapter 8 may still matter for a UK intermediary, and UK tax/NIC exposure must be considered.
An agency can carry fee-payer and deemed-employer responsibilities even if the agency itself is small. The SDS must pass through the relevant chain, and payment details need to be recorded correctly.
Contracts matter. What happens during delivery matters just as much.
A status assessment evaluates the overall relationship. No single phrase, checklist or commercial label reliably determines the answer. Evidence should reconcile contractual rights with actual practice rather than select only facts favourable to one outcome.
Is the worker required personally?
Consider whether the individual must perform the work, and whether any right to send a substitute is genuine, meaningful and compatible with how the engagement actually operates.
Who has the right to direct the work?
Examine control over what must be done and how, when and where it is done. Specialist autonomy alone does not remove a client’s possible contractual right of control.
What have both sides promised?
Look at the obligation to provide and perform work during the engagement, any commitment to offer further work, availability expectations, notice provisions and the overall contractual framework.
Who carries business risk?
Review fixed-price deliverables, rectification at the supplier’s cost, professional indemnity insurance, unreimbursed expenditure and whether genuine commercial risk is present.
How independent is the service?
Consider team structures, managerial reporting, internal policies, benefits, equipment, branding and whether the individual is integrated into the client organisation.
Is there a business on its own account?
Multiple customers, marketing, investments, invoicing and business infrastructure can be relevant—but no one indicator overrides the rest of the evidence.
For official explanation of personal service, genuine substitution and control, see the HMRC Employment Status Manual. A written clause that does not reflect the real relationship may carry little or no weight.
Six stages from responsibility to an explainable tax outcome.
We aim for proportionate, documented work rather than a predetermined inside/outside result. The scope of advisory support is agreed first, and complex employment-law or litigation matters may require specialist legal advice.
Identify the actual parties.
Establish the end client, worker, intermediary, fee-payer and any agencies. Confirm whether the arrangement involves a personal service company or another intermediary and whether a UK tax/NIC liability is relevant.
Determine which legal regime applies.
Check public versus private sector, small-client treatment, wholly overseas clients, applicable company-size tests and supply-chain structure. Responsibility is not assumed from the contractor’s own company size.
Read both contract and real practices.
Review statements of work, communications, control, personal service, substitution, mutual obligations, financial risk and how work is actually delivered. Identify inconsistencies rather than relying on labels.
Document a defensible status analysis.
Where appropriate, use HMRC CEST as part of the factual assessment. Explain material factors, ambiguities, the overall status rationale and any records that are missing.
Connect the outcome to tax and payroll.
For inside engagements, identify the deemed employer and the PAYE/NIC approach. For Chapter 8 engagements, examine the intermediary’s possible deemed payment and connected company accounts.
Revisit material changes and disputes.
Retain the rationale, review any valid SDS disagreement, update documentation after changes in working practices and keep contractors’ accounting and tax treatment aligned with the underlying facts.
A client-led decision must be reasoned, communicated and capable of review.
Where Chapter 10 applies, the client needs to take reasonable care in forming a status determination and give the worker and the relevant contracting party an SDS explaining the conclusion. Processes that merely stamp every worker “inside” or “outside” without considering the engagement create avoidable risk.
Identify the engagement and assess the overall status, applying reasonable care. Record the outcome and why the facts support it.
Give the worker and the party with whom the client contracts the SDS. A supply chain may involve additional forwarding before the fee-payer receives it.
The worker or deemed employer may challenge the SDS with reasons. The end client considers the representations and can seek further facts.
Continue operating the existing status determination while the disagreement is assessed; the tax treatment is not automatically suspended.
Confirm the original decision with reasons or withdraw it, issue a new SDS and explain its effective date. Failure to respond can shift deemed-employer responsibility.
Keep the SDS, supporting evidence, CEST answers if used, correspondence, payments and the rationale for any later change in status.
The tax consequence must follow the correct party and the correct contract.
An inside determination changes the tax handling of relevant fees; it does not automatically close a personal service company, rewrite employment rights or turn every payment into the same type of income. We connect the status question to the records and roles behind the transaction.
Connect the SDS to your company accounts and personal tax.
Ask who made the determination, whether your client is small, which fee-payer has deducted tax, and what is included in the gross and net amounts. Review salary/dividend treatment and avoid recording already-taxed amounts in a way that produces unnecessary double taxation. If the engagement is under Chapter 8, the intermediary may need to calculate its own deemed employment payment.
Britvex can consider the accounting and Corporation Tax consequences within an agreed scope. A separate self-assessment review may be needed for other income, student-loan repayments or personal circumstances.
Annual accounts →Make responsibility visible throughout the supply chain.
Identify who issues the SDS and who actually pays the intermediary. When Chapter 10 applies and the status is inside, the deemed employer generally deducts Income Tax and employee National Insurance from the relevant deemed direct payment, and accounts for employer National Insurance and any applicable Apprenticeship Levy separately.
Employer liabilities are not ordinarily amounts to deduct from the worker’s contractual deemed direct payment. Invoicing, VAT, payroll reporting, chain communications and record retention should be considered together.
Payroll services →A sound review records the reasoning — and knows when to revisit it.
The status of a project can change during delivery. A revised statement of work, new management oversight, different substitution rights or an extension may alter the facts. A historic SDS or CEST result should not be treated as a permanent guarantee.
HMRC Check Employment Status for Tax (CEST)
CEST is HMRC’s own decision-support tool for employment-status assessments. HMRC says it will stand by a result when the answers are accurate and the tool has been used in accordance with its guidance. A result can be inconclusive, and a result based on an incomplete description of the work is not a substitute for understanding the facts. Save the answers and output; HMRC does not retain them for you.
Wholly overseas clients
For a private-sector client wholly outside the UK with no qualifying UK connection, the client-led Chapter 10 rules generally do not apply. That is different from saying the engagement is free of UK tax obligations: the worker’s intermediary may still need to consider Chapter 8, and any UK tax or National Insurance position depends on the circumstances. See overseas founders for broader UK company support.
HMRC enquiries, liabilities and set-off rules
If HMRC later finds that an engagement was treated incorrectly, the relevant party may face PAYE and National Insurance assessments, interest and other consequences depending on the case. The post-April 2024 set-off framework can, subject to specific conditions and HMRC’s decision, reduce a deemed employer liability to recognise some tax and NIC already paid or assessed by the worker or intermediary on the same income; it is not automatic relief or a reason to skip proper compliance.
Changes in working arrangements
Renewals and substantial changes should prompt a fresh look at the contract and day-to-day evidence. Keep written records of the people consulted, relevant documents, status reasoning, any revised SDS and the tax treatment applied before and after the change.
The best starting point is a complete picture of the engagement.
An IR35 opinion cannot be grounded in the contract title alone. A useful first review should include the end-client position, agreements, actual working practices and any status decision already issued.
Contracts, schedules, extensions and specifications showing what has been promised and to whom.
The organisations in the supply chain, who receives the services and who makes the payment.
Any status statement, reasons, saved tool answers, disagreement correspondence or previous opinions.
Who directs tasks, whether a substitute can genuinely attend, availability expectations and who bears costs.
Fee arrangements, invoices, deductions, expenses and payroll or company bookkeeping data where relevant.
Contract renewals, revised working patterns, overseas connections and anything that differs from the written agreement.
IR35 should not sit apart from accounting, payroll or the company behind it.
After a status assessment, the practical questions are often about bookkeeping, correct deductions, accounts, company tax and how the arrangement is documented. These existing Britvex services support the wider financial record.
Documented judgements. Clear responsibilities. No invented certainty.
Britvex is a UK accountancy, tax, advisory and compliance business. We distinguish accounting/tax support from specialist employment-law representation and do not promise that HMRC or a tribunal will agree with a particular status conclusion.
IR35 questions that change real tax decisions.
These answers explain general UK rules, not a determination for a particular contract. The facts, relevant tax year, client size and contractual chain must be assessed before acting.
What is IR35 in the UK?
IR35 refers to the off-payroll working and intermediaries tax rules. They consider whether a person supplying services through their own intermediary would have been an employee for tax purposes if engaged directly. The responsibility for deciding and operating the rules depends on the end client and the engagement.
Who decides whether a contract is inside or outside IR35?
For public-sector clients and medium or large private-sector clients, the end client normally determines status and issues a reasoned status determination statement (SDS). For small private-sector clients, or qualifying wholly overseas clients, the worker’s intermediary normally assesses whether the older Chapter 8 IR35 rules apply.
Does IR35 apply to every limited company contractor?
No. An intermediary alone does not mean a contract is inside IR35. The actual terms and working practices of each engagement must be considered. One contractor may have separate contracts with different status outcomes.
Does an outside-IR35 contract guarantee the worker is self-employed?
No. Contract labels, invoices and a limited company structure are not decisive. Employment status for tax depends on the full contractual relationship and what happens in practice. Employment rights and tax status can also differ.
What is a status determination statement (SDS)?
An SDS records the end client’s employment-status conclusion and the reasons for it. Where the Chapter 10 client-led rules apply, the end client must take reasonable care and provide the SDS to the worker and the relevant contracting party. An unsupported label or generic template may be inadequate.
What if I disagree with an inside-IR35 determination?
A worker or deemed employer may give reasons for disputing the SDS through the client-led process. The client must respond within 45 calendar days of receiving a valid disagreement. The existing determination continues to be applied while the disagreement is considered, and a disagreement may be raised before the final payment for the engagement.
Does the contractor have only 45 days to appeal?
No. The 45-calendar-day requirement is the client’s response deadline after receiving a valid disagreement. It is not a universal 45-day window for the worker to raise an objection. The statutory disagreement process has its own timing rules.
Is the end client always responsible for PAYE and National Insurance?
No. Under the client-led rules, the deemed employer is generally the fee-payer immediately above the worker’s intermediary, which may be an agency or the end client. The deemed employer operates PAYE and relevant National Insurance on deemed direct payments when the engagement is inside the rules; liability can shift if statutory obligations are not met.
Can a small business engage contractors outside IR35?
A small non-public-sector end client is generally outside the Chapter 10 client-led status-determination obligations. That does not make every engagement outside IR35: the worker’s intermediary may instead need to assess and account for the engagement under Chapter 8.
Have the small-company IR35 thresholds changed?
Yes. Company-size thresholds were raised for financial years beginning on or after 6 April 2025, but HMRC says those changes cannot affect off-payroll responsibility before 6 April 2027 at the earliest. The relevant accounts, two-year rules, group arrangements and tax-year timing must be checked.
Can an HMRC CEST result be relied on?
HMRC says it will stand by a CEST determination when the answers accurately reflect the engagement and its guidance is followed. CEST can be inconclusive. Keep the full answers and result and reassess if the actual working arrangements change.
What happens if my client is entirely overseas?
Where a private-sector client is wholly outside the UK and has no UK connection within the relevant statutory test, Chapter 10 will not normally apply. The worker’s intermediary may still have Chapter 8 obligations. International facts and UK tax/NIC exposure need individual review.
Does working inside IR35 make me an employee with employment rights?
Not automatically. Being treated as employed for Income Tax and National Insurance under the off-payroll working rules does not itself create employment rights such as statutory holiday pay or unfair-dismissal protection. Employment-rights status is assessed separately.
What evidence should I send Britvex for an IR35 review?
Start with the written contract and statements of work, the end client and agency details, any SDS or CEST output, the real working arrangements, substitution rights, control over work, financial risk, invoicing and payment information, and correspondence about a status dispute. We confirm the scope of any review before proceeding.
Need an IR35 review based on your actual engagement?
Tell Britvex who the end client is, whether an SDS has been issued and which part of the contract or tax treatment is unclear. We will identify the next step and confirm the scope of professional support before work begins.
Official regulatory sources: HMRC overview · End-client responsibilities · Small-client engagements · CEST · Status disagreement process · Size-threshold timing. Information reflects guidance checked 29 October 2026. Individual advice depends on the facts and applicable law.