Skip reasonable care on IR35 status and the tax bill returns to the client

News · End-Hirers & Recruitment Agencies · OPRaaS Platform

An IR35 status determination is meant to be a judgement about one person’s working arrangement. In practice, across large parts of the contractor market, it has hardened into a blanket setting applied to a whole category of people who work through a personal service company, and the people it is applied to are paying for that caution in hard cash.

That cost has now been put in numbers. Research by IPSE, the self-employed trade body, and the tax specialist Qdos, reported this week by The Global Recruiter, found that contractors assessed by their clients as employed for tax purposes estimate they have paid, on average, £44,000 more in tax as a result of the off-payroll working reforms.

The mechanism is simple, and it cuts both ways. When a client decides that a whole category of contractors sits inside the rules rather than weighing each engagement on its facts, the contractor carries a tax outcome they dispute. Under HMRC’s own rules, the client that made that blanket call may not have made a valid determination at all.

What a risk-averse IR35 status determination actually costs

The IPSE and Qdos research is a snapshot, not a census. It draws on 184 contractors, so the figures are self-reported estimates rather than audited losses, and they are best read that way.

Even hedged, the spread is striking. According to IPSE and Qdos, more than one in five of those surveyed put the extra tax at between £20,000 and £29,999, and around one in eight put it at more than £100,000 since the reforms took effect.

The study also leaves out the assignments contractors simply turned down rather than accept a status they rejected, which, on the researchers’ account, would take the true figure higher still.

The headline number belongs to the contractor. That is where a cautious IR35 status determination bites first, and it is why the contractor picks up the tab in the market’s telling. The client’s exposure is quieter, and it comes next.

Why a blanket call fails HMRC’s reasonable care test

Here is the part the headline figure understates. A risk-averse determination is not only expensive for the contractor. It can also be invalid.

HMRC’s published guidance is explicit on the point. Its Employment Status Manual states that a blanket approach, deciding that a group of contractors falls inside the rules because they do similar work under similar terms, does not meet the reasonable care standard the legislation requires.

Where a client fails to take reasonable care, HMRC’s position is that the determination is not valid and the responsibility for the tax, National Insurance and Apprenticeship Levy rests with the client rather than a party further down the chain.

The cost of getting this wrong at scale is already on the public record. The National Audit Office reported that central government bodies had paid or owed around £263 million to HMRC for administering the rules incorrectly, some departments accounting for tens of millions each, in its investigation into the IR35 reforms. That was the public sector running head-on into the same reasonable-care standard private-sector clients now work to.

The rules themselves sit in Chapter 10 of Part 2 of the Income Tax (Earnings and Pensions) Act 2003, and they turn on a Status Determination Statement that the client must reach with reasonable care and pass down the chain. A determination reached by default, applied across the board, is exactly the pattern HMRC’s guidance describes as falling short.

Where IR35 status determination sits in the labour supply chain

For an end-hirer or a recruitment agency, this is the moment an IR35 status determination stops being a tax technicality and becomes a labour supply chain question. Status is a fact, not a setting.

Every determination is a link in a chain. The client decides status, the agency contracts on the back of that decision, and the fee-payer operates PAYE or does not. If the call at the top is a blanket setting rather than a reasoned one, the exposure passes upstream to whoever HMRC judges failed to take care, and every party building on that call inherits the weakness.

The assurance gap is not whether a determination was made. It is whether it was made with care, recorded at the time, and capable of being produced when someone asks. That is a very different discipline from ticking a box in an onboarding form, and it is where a cautious blanket policy and a careful evidenced one sharply come into focus as opposites.

From a one-off form to an evidenced IR35 status determination

This is the territory the OPRaaS Labour Supply Chain Assurance course covers in Module 3, under its Contingent Workforce Tracking topic, where workforce classification has to be documented and supported by evidence rather than assumed. An email is not an evidence trail.

The course frames it as a set of questions a business should be able to answer at any time. Are workers correctly classified, as agency worker, umbrella employee, contractor through a personal service company, or genuinely self-employed? Is that classification documented and supported by evidence? Can the organisation produce a compliant headcount report within 24 hours for audit purposes? A cautious IR35 status determination that lives in a filing decision made months ago rarely survives those three questions.

What turns a determination from a form into a record is contemporaneous detail. A defensible IR35 status determination shows who assessed the engagement, on what status factors, on what date, and can be retrieved on demand rather than reconstructed under enquiry. That is the difference between an assertion and an evidenced position.

How the OPRaaS Virtual Compliance Director runs IR35 status determination

OPRaaS, On-Pay-Roll-as-a-Service, is a systemised governance and workforce management partner for organisations that rely on temporary, contractor and contingent labour. Through the OPRaaS Virtual Compliance Director (OPRaaS VCD) solution we embed senior governance leadership into your business without the cost of a full-time director, building audit-ready controls across IR35, CIS, GLAA, modern slavery and HMRC’s wider labour supply chain expectations, for end-hirers, recruitment agencies, umbrella companies, managed service providers and public sector buyers.

For an IR35 status determination, that discipline is operational rather than abstract. Status determinations and right-to-work checks are captured at onboarding and re-run on contract renewal inside the platform, so a determination is a live record that moves up the chain to the agency and the client, not a form filed once and forgotten. The check is live, not annual.

Personal service companies and labour intermediaries are monitored for director and ownership changes at Companies House and for credit-risk changes at Creditsafe, so a supplier drifting toward a phoenix or missing-trader pattern is flagged before the next payment run rather than after a strike-off.

This is the discipline the OPRaaS Map, Train, Audit and Evidence platform is built to run. The checks are mapped, the team is trained, each engagement is audited against the status test, and the audit and evidence summary the OPRaaS VCD platform produces on demand is the record that lets a board own its compliance as an asset rather than scramble for it under enquiry.

OPRaaS is approved on the UK Government Commercial Agency (formerly Crown Commercial Service) frameworks including RM6310 Audit & Assurance Services (Lots 2 & 4), RM6219 Learning & Training Services DPS, and RM6237 Learning & Training Services DPS.

A determination reached with care spares the contractor an unfair bill and the client an unexpected one, and the same evidence stands behind both.

What boards and agencies should check before the next engagement

The policy argument, over whether the off-payroll rules should be reformed or reversed, will run for another Budget cycle at least. IPSE and Qdos read their own findings as a case for another look at the rules, and that debate belongs to government.

For a board or an agency signing off the next contractor engagement, the near question is narrower and more useful. Can you show, engagement by engagement, that each IR35 status determination was reasoned, recorded and retrievable? The same question runs across public sector buyers, whose earlier errors the National Audit Office already counted in the hundreds of millions.

The blanket call looks like the cautious option. On HMRC’s own reading it can be the exposed one, because a determination made by default is a determination made without care. A reasoned, evidenced determination is what comes out ahead when scrutiny arrives, whichever direction the policy eventually takes.

Compliance is your asset. Evidenced daily.

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Drawing on The Global Recruiter’s report of the IPSE and Qdos survey of contractors, published on 16 July 2026; HMRC’s Employment Status Manual guidance on reasonable care and the Status Determination Statement on gov.uk; the National Audit Office investigation into the implementation of the IR35 reforms; and Chapter 10 of Part 2 of the Income Tax (Earnings and Pensions) Act 2003, read alongside the OPRaaS LSCA Self-Certification Course Module 3, Contingent Workforce Tracking.