IR35 (the intermediaries legislation) does not contain its own statutory definition of what “employment” is.
When an IR35 case reaches a tribunal, judges apply the same common-law employment status tests developed through years of court decisions.
This guide explains how the main authorities fit together and how tribunals use them when deciding IR35 and employment status disputes.
The level of court also matters. Supreme Court and Court of Appeal decisions are binding on lower courts and tribunals, while Upper Tribunal decisions bind the First-tier Tribunal on points of law. First-tier Tribunal decisions, by contrast, do not create binding precedent.
Core authorities used in IR35 disputes
| Case | Court | Year | Key principle | Judgment |
|---|---|---|---|---|
| Ready Mixed Concrete (South East) Ltd v Minister of Pensions and National Insurance | High Court | 1968 | The three-limb test: personal service for remuneration, sufficient control, and other terms consistent with employment. Read our summary. | ESM7030 |
| Market Investigations Ltd v Minister of Social Security | High Court | 1969 | Established the classic “business on your own account” test still used in employment status disputes. Read our summary. | GOV.UK |
| Autoclenz Ltd v Belcher | Supreme Court | 2011 | Important authority on identifying the parties’ true agreement, although Atholl House confirmed that its worker-rights approach cannot simply be used to disregard contractual terms in IR35 tax cases. Read our summary. | Supreme Court |
| Hall v Lorimer | Court of Appeal | 1994 | Leading authority on considering the overall picture and wider business activity. Read our summary. | ESM7160 |
| HMRC v Atholl House Productions Ltd (Kaye Adams) | Court of Appeal | 2022 | Established the modern three-stage framework for IR35 analysis and clarified how to evaluate wider business activity. Read our summary. | BAILII |
| HMRC v Professional Game Match Officials Ltd (PGMOL) | Supreme Court | 2024 | Confirmed that minimum mutuality can exist during individual engagements where work is offered and accepted, although overall status still requires the full Ready Mixed Concrete test. Read our summary. | Supreme Court |
| Kickabout Productions Ltd v HMRC | Court of Appeal | 2022 | Tribunals must assess the hypothetical contract as a whole rather than relying on a single decisive factor. Read our summary. | BAILII |
How the leading cases are used in IR35 disputes
Ready Mixed Concrete (1968) – the three-limb test
Ready Mixed Concrete remains the starting point for employment status.
For a contract of employment to exist, the worker must provide personal service in exchange for remuneration, the client must have sufficient control, and the other terms of the relationship must be consistent with employment.
Those conditions still sit at the heart of IR35 status decisions.
Read our Ready Mixed Concrete summary.
Market Investigations (1969) – business on your own account
Market Investigations produced one of the best-known questions in employment status law: is the individual in business on their own account?
The court considered financial risk, investment, and the responsibilities the individual took on as part of the business.
The same question remains relevant when a tribunal considers a contractor’s wider commercial activity.
Read our Market Investigations summary.
Autoclenz Ltd v Belcher (2011) – limits in IR35 cases
Autoclenz is an important employment-status authority, but its application to IR35 tax disputes is limited.
In Atholl House, the Court of Appeal confirmed that the special approach adopted in Autoclenz for statutory worker-protection cases does not apply in the same way when determining employment status for income tax purposes.
In an IR35 case, contractual terms cannot simply be disregarded because the parties did not exercise them in practice. Ordinary principles of contractual interpretation apply when establishing the actual terms and constructing the hypothetical contract.
Substitution is a good example. A genuine contractual right does not disappear simply because nobody has exercised it.
Hall v Lorimer (1994) – genuine business activity
Hall v Lorimer involved a freelance television vision mixer who worked for several clients.
His varied income, financial risk, equipment, and wider working arrangements supported the view that he was running an independent business.
The Court of Appeal looked at the whole picture rather than trying to determine status based on a single factor.
The case remains useful where a contractor’s wider commercial activity forms part of the circumstances properly taken into account when assessing the engagement.
Read our Hall v Lorimer summary.
HMRC v Atholl House Productions Ltd (Kaye Adams)
Atholl House reached the Court of Appeal in 2022, establishing the modern three-stage framework for IR35 analysis.
The Court of Appeal allowed HMRC’s appeal and remitted the case. When the First-tier Tribunal reconsidered it in 2024, it again found that Adams’ engagements fell outside IR35.
Her wider commercial activity and overall working arrangements were relevant to the final assessment, within the proper analysis of the hypothetical contract.
Read our Atholl House summary.
HMRC v PGMOL (Supreme Court 2024) – mutuality clarified
PGMOL dealt directly with mutuality of obligation and control.
The Supreme Court found that the minimum mutual obligations required for an employment relationship were present during individual engagements once a referee accepted an appointment. It also found that there was a sufficient framework of control for the employment test to be considered.
That did not mean the referees were automatically employees. The Supreme Court did not decide their final employment status and sent the case back to the First-tier Tribunal to apply the remaining Ready Mixed Concrete analysis.
On remittal, the First-tier Tribunal concluded in May 2026 that the individual match engagements were contracts for services rather than contracts of employment. Although the necessary mutuality and control were present, the wider factors considered at the third stage of the Ready Mixed Concrete test pointed away from employment.
Kickabout Productions Ltd v HMRC (2022) – the overall picture
Kickabout involved Talksport presenter Paul Hawksbee and reached the Court of Appeal in 2022.
The decision confirmed that an IR35 case cannot normally be settled by picking one favourable or unfavourable status factor.
The tribunal must construct the hypothetical contract and then evaluate whether that contract, considered as a whole, is one of employment.
The full collection of reported IR35 disputes and wider employment-status authorities is available in our IR35 Case Law Library, with each case listed by court level and its practical significance.
How tribunals approach IR35 cases
Recent authorities such as Atholl House, Kickabout, and PGMOL have clarified the sequence tribunals should follow.
A tribunal will normally:
- Establish the terms of the actual contractual arrangements and the relevant factual circumstances in which the worker provided the services.
- Construct the hypothetical contract that would have existed if the worker had contracted directly with the end-client.
- Apply the common-law employment status tests to that hypothetical contract, including whether the necessary mutual obligations involving personal service for remuneration and sufficient control are present.
- If those necessary conditions exist, evaluate the remaining terms and circumstances to decide whether, viewed overall, the hypothetical contract is one of employment.
The first two Ready Mixed Concrete conditions are necessary, but not sufficient on their own, to establish an employer-employee relationship. They require mutual obligations involving personal service in return for payment, together with a sufficient degree of control. If both conditions are satisfied, the tribunal then considers the other terms and circumstances to decide whether the hypothetical contract would make the individual an employee.