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IR35 Status Disputes: How to Challenge a Determination

If you disagree with an IR35 status determination, you have a structured route to challenge it — from the client's internal process through to the First-Tier Tribunal. Here is how each stage works.

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This is general guidance, not legal or tax advice. IR35 disputes are fact-specific and the financial exposure can be significant. Seek specialist tax advice or legal representation before taking formal action against a determination. Read our full disclaimer.

Why IR35 disputes happen

IR35 status disputes typically arise in two ways. First, a medium or large media client may issue a Status Determination Statement (SDS) under the off-payroll working rules that the freelance journalist believes is wrong — often a blanket “inside IR35” determination applied across many contractors without regard to the specific facts of each engagement. Second, HMRC may open a compliance check into a personal service company's (PSC's) historical tax position and conclude that past engagements should have been treated as inside IR35.

Both routes have a formal challenge process. Understanding which stage you are at — client disagreement, HMRC compliance check, statutory review, or Tribunal — determines what evidence you need and how quickly you need to act, since several of these stages carry strict time limits.

Step one: the client status disagreement process

Under Chapter 10 of ITEPA 2003, a medium or large client issuing an SDS must operate a status disagreement process, allowing you (or the fee-payer) to challenge the determination. You should set out clearly why you believe the engagement is outside IR35, referencing the specific working practices — the actual level of control exercised, whether there is a genuine right of substitution, and whether there is mutuality of obligation between commissions.

The client has 45 days to respond with either a revised determination or reasons for maintaining the original one. If they fail to respond within that window, responsibility for the status decision — and any resulting liability if it later proves wrong — shifts from the fee-payer to the client. This deadline is a meaningful piece of leverage and should be tracked carefully.

Appealing a formal HMRC determination

Written appeal within 30 days

If HMRC issues a formal decision, assessment, or determination — typically following a compliance check into your PSC's tax affairs — you generally have 30 days from the date of the decision to appeal in writing, setting out clearly why you disagree and on what grounds.

Statutory review

HMRC may offer an internal statutory review, carried out by an officer who was not involved in the original decision. This is a genuine opportunity to have the decision reconsidered before matters escalate further, and can resolve disputes without needing to go to Tribunal.

Alternative Dispute Resolution (ADR)

In some cases HMRC will consider ADR, using an independent, HMRC-trained mediator to help both sides reach agreement outside formal litigation. It does not replace your right to a statutory review or Tribunal appeal but can be a useful, lower-cost step where there is a realistic prospect of agreement.

The First-Tier Tribunal (Tax Chamber)

  • 1When a case reaches the Tribunal: If a statutory review does not resolve the dispute, or you decide to bypass it, you can appeal directly to the First-Tier Tribunal (Tax Chamber), the independent judicial body that hears tax appeals, including IR35 status cases.
  • 2What the Tribunal examines: The Tribunal looks at the substance of the actual working relationship — not just the contract wording — considering control, mutuality of obligation, substitution, financial risk, integration into the client's organisation, and other factors drawn from established employment-status case law.
  • 3Evidence and representation: Cases typically involve documentary evidence (contracts, correspondence, invoices, diaries showing how work was actually allocated and controlled) and witness evidence describing day-to-day working practices. Given the complexity, specialist tax representation is strongly advisable at this stage.

Settlement negotiation with HMRC

HMRC's Litigation and Settlement Strategy allows negotiated settlements in appropriate cases, and a significant proportion of IR35 disputes are resolved this way rather than through a full contested Tribunal hearing. A negotiated settlement can reduce legal costs, shorten the time to resolution, and provide certainty, but it may still involve paying a material sum in back tax, National Insurance, and interest.

Never agree a settlement figure with HMRC without independent specialist tax advice on whether it fairly reflects your actual liability under the case-by-case IR35 tests.

Why IR35 cases are decided one at a time, not by checklist

There is no single decisive factor in an IR35 status dispute. HMRC and the Tribunals look at the whole picture of the working relationship as it actually operated, not merely at what the contract says. A written substitution clause that both parties know would never genuinely be exercised carries little weight; a verbal understanding that closely tracked employment-style control can outweigh contractual language suggesting independence.

This case-by-case approach cuts both ways for journalists: a blanket “inside IR35” determination applied to every freelancer at a client is vulnerable to challenge precisely because it ignores individual facts, but equally, a freelancer cannot rely solely on a well-drafted contract if their actual working practices look like employment in substance.

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Frequently asked questions

What do I do first if I disagree with an IR35 status determination?
Use the client's status disagreement process first. Under the off-payroll working rules, a medium or large client issuing a Status Determination Statement (SDS) is legally required to have a process for you to challenge it, setting out why you believe the determination is wrong, ideally referencing the specific working practices (control, substitution, mutuality of obligation) that support an outside-IR35 position. The client must respond within 45 days; if they do not, responsibility for any resulting tax liability shifts to them.
Can I appeal an IR35 determination directly to HMRC?
The client disagreement process is separate from a formal HMRC appeal. If HMRC itself opens a compliance check or issues an assessment or determination (for example, following an investigation into a PSC's tax position), you generally have 30 days from the date of the decision to appeal in writing, explaining why you disagree. HMRC may then offer a statutory review by an independent HMRC officer not involved in the original decision, or the matter can proceed towards the tax tribunal.
What is the First-Tier Tribunal (Tax) and when would my case go there?
The First-Tier Tribunal (Tax Chamber) is the independent judicial body that hears appeals against HMRC tax decisions, including IR35 status disputes, when they cannot be resolved through HMRC's internal review process. Cases typically reach the Tribunal after a compliance check, a formal HMRC determination, and an unsuccessful statutory review. Tribunal proceedings involve submitting evidence about the actual working relationship — contracts, correspondence, and witness evidence about how the engagement really operated in practice.
Is it possible to settle an IR35 dispute with HMRC without going to Tribunal?
Yes. HMRC operates a Litigation and Settlement Strategy that allows for negotiated settlements in appropriate cases, and many IR35 disputes are resolved this way rather than through a full Tribunal hearing, particularly where there is genuine uncertainty or mixed evidence about status. Settlement can reduce cost, time, and uncertainty compared with contested litigation, but any settlement should be considered carefully, ideally with specialist tax advice, since it may still involve a significant liability.
How is each IR35 case actually assessed — is there a fixed checklist?
No single factor is decisive. HMRC and the Tribunals assess the whole picture of the actual working relationship on a case-by-case basis, weighing control, mutuality of obligation, the right of substitution, financial risk, provision of equipment, and how integrated the individual is into the client's organisation, among other factors drawn from case law. This is why generic advice has limits — the specific facts of your engagement, not just the contract wording, determine the outcome.
Should I get professional representation for an IR35 dispute?
Specialist tax advice is strongly recommended once a dispute moves beyond an initial status disagreement letter to the client. IR35 case law is detailed and fact-specific, HMRC compliance checks can be lengthy and technical, and the financial exposure (tax, National Insurance, interest, and potentially penalties) can be substantial. The NUJ can offer general guidance to members, but a contentious HMRC investigation or Tribunal appeal typically needs a specialist tax adviser or solicitor experienced in IR35 litigation.

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