IR35 has never been a settled area of law, and if you have been following tribunal activity over the past two years, you will know that 2024 and 2025 produced some of the most significant case law we have seen in a long time.
Whether you are an employer engaging contractors, a payroll professional, or an HR lead trying to get your house in order, the direction of travel is worth understanding.
We have pulled together five of the most important recent decisions, explained what the courts actually decided, and set out what each ruling means in practice.
George Mantides Ltd v HMRC (Upper Tribunal, April 2025)
Outcome: HMRC wins
Dr George Mantides is a consultant urologist who worked as a locum through his personal service company for two NHS trusts. The case ran for several years and went through multiple rounds of appeal, partly because a key question about how to interpret Mutuality of Obligation (MoO) could not be resolved until the
Supreme Court addressed it in PGMOL – more on that below.
The Upper Tribunal’s final decision, published in April 2025, confirmed that the engagement with Royal Berkshire Hospital was inside IR35. Even though the contract was short-term and terminable by either party, the tribunal found there was sufficient mutuality from the moment the locum sessions were booked and carried out.
What this means in practice
Do not assume that the absence of formal employment rights, such as no sick pay, no holiday pay and no guaranteed hours, automatically places a contractor outside IR35.
Tribunals look at the practical reality of the arrangement. If work is being offered and accepted on a regular basis, that can be enough to establish mutuality of obligation.
Bryan Robson Ltd v HMRC (First-tier Tribunal, 2024/2025)
Outcome: Partial HMRC win
Yes, that Bryan Robson. The former Manchester United captain and England international found himself in an IR35 dispute with HMRC over his ambassadorial services to the club, provided through his personal service company. The tribunal ruled that the ambassadorial element of his work, which included attending events, visiting executive boxes, and representing the club on matchdays, fell inside IR35.
The factors that counted against him included;
- The club controlled his schedule
- The club determined which boxes he visited
- They also required him to appear on the pitch at specific times
- There was very little evidence of him working for other clients during the relevant period, which pointed towards financial dependency on Manchester United.
The tribunal did accept that a small proportion of fees related to genuine image rights, and that portion fell outside IR35.
What this means in practice
Integration into a client’s operations is a significant indicator of employment. If a contractor is rostered, managed, and directed in much the same way as a member of staff, even without a formal employment contract, HMRC will scrutinise that arrangement carefully.
The image rights point is also worth noting, but the tribunal was clear – image rights must be real, separable, and properly valued. They cannot be used as a blanket defence for what is essentially personal service income.
PGMOL v HMRC (Supreme Court, September 2024)
Outcome: HMRC wins on Mutuality of Obligation
Strictly speaking, this is an employment status case rather than a classic IR35 case. It concerns whether football referees working for the Professional Game Match Officials Limited were employees. But its significance for IR35 cannot be overstated.
The Supreme Court’s ruling in September 2024 has fundamentally changed how Mutuality of Obligation is interpreted. Previously, contractors and advisers could argue that where either party was free to cancel an engagement, and neither was truly obligated to offer or accept work, there was no MoO.
The Supreme Court disagreed. It confirmed that a basic exchange of work for pay is sufficient to establish mutuality, even within a short engagement. That mutuality exists from the point the work is accepted, runs through the engagement, and ends when the final obligations are completed.
What this means in practice
This is the most consequential ruling in the group. Mutuality of Obligation had long been used as a route out of IR35, particularly for contractors on short-term or ad-hoc engagements. That argument is no longer available.
If your business has historically relied on the absence of ongoing obligations as its primary outside-IR35 position, that approach needs revisiting. The three-stage employment status test must now be applied with the Supreme Court’s interpretation firmly in mind.
S & L Barnes Ltd v HMRC (Upper Tribunal, 2024)
Outcome: HMRC wins on appeal
Stuart Barnes, the former Bath and England rugby player, now a Sky Sports pundit, initially won his IR35 case at the First-tier Tribunal. The FTT found that he was genuinely in business on his own account, with sufficient autonomy and flexibility in his working practices to sit outside IR35.
HMRC appealed, and the Upper Tribunal reversed the decision. Where the FTT had focused heavily on Barnes’s real-world working practices, the UT placed much greater weight on the contractual terms. Specifically, Sky’s contractual right of first call on his services and its control over scheduling and appearances were seen as pointing firmly towards employment.
What this means in practice
This case is a useful reminder that contracts and working practices need to be consistent. Good working practices will not protect you if your written contract contains terms that look like employment. Equally, a clean contract on paper will not help if the day-to-day reality tells a different story. Both need to reflect the same arrangement.
Mainpay Ltd v HMRC (Court of Appeal, 2025)
Outcome: HMRC wins
This case sits slightly outside the classic IR35 frame as it concerns umbrella companies rather than a personal service company arrangement. Mainpay argued that its workers were employed under a single overarching contract, which would have made each individual assignment location a temporary workplace, allowing travel and subsistence expenses to be claimed tax-free. That would have been a significant financial advantage for the umbrella and the workers on its books.
The Court of Appeal rejected this comprehensively. There was no genuine overarching contract in place, and the workers’ individual assignments were their normal places of work. The tax relief did not apply.
What this means in practice
For businesses working with umbrella companies, this case underlines the importance of using reputable, compliant providers.
At Ascend, we only work with umbrella companies that are either FCSA-accredited or have passed our own audit process, precisely because schemes like the one in Mainpay create real risk – for the worker, for the agency, and potentially for the end-hirer.
What the courts are telling us
Reading these five cases together, a clear pattern emerges. The courts are consistently siding with HMRC, applying established principles with increasing confidence, and closing off arguments that contractors and advisers have relied on for years.
Mutuality of Obligation is no longer a reliable defence. Substitution clauses carry limited weight unless they are genuinely practicable and have actually been used. Control, both contractual and practical, remains the most determinative factor. And tribunals continue to scrutinise the gap between what a contract says and how a working relationship actually operates.
This does not mean that outside-IR35 determinations are impossible. Genuine contractors with real autonomy, genuine business structures, and well-drafted contracts continue to succeed. But the bar is higher than it was, and the cost of getting it wrong is significant.
Questions every business should be asking
If you engage contractors, now is a good time to review those arrangements honestly. The following questions are worth working through before you issue or renew any contractor engagement.
On your contracts
- Do the written terms genuinely reflect how the relationship works in practice?
- Does the contract contain any clauses that imply employment – guaranteed hours, paid leave, or integration into line management structures?
- Is there a genuine, practicable right of substitution, and has it ever been used?
On your working practices
- Who controls how, when, and where the contractor works?
- Is the contractor integrated into your workforce – using your systems, attending your team meetings, holding a company email address
- Does the contractor work for multiple clients, or are they financially dependent on your organisation?
On your process
- Have you issued a Status Determination Statement, and do you have a formal dispute resolution process in place?
- Are your determinations documented and based on reasonable care?
- If you work with an umbrella company, is it FCSA-accredited or independently audited?
If any of these give you cause for concern, it is better to address them now rather than wait for an HMRC enquiry.
IR35 is genuinely complex, and the case law is moving quickly. If you are unsure whether your current contractor arrangements stand up to scrutiny, or if you want to make sure your payroll processes are set up correctly for both inside and outside-IR35 engagements, get in touch with the team at Ascend. It is
exactly the kind of complexity we deal with every day.
