IR35 in 2026: When Your UK Contractor Is Really an Employee

You hired a UK contractor who invoices through their own limited company. HMRC can treat that person as employed for tax. Whether the bill lands on you or on them comes down to your size, your paperwork, and where you are registered. Here is how the 2026 rules decide it.

IR35 is the UK tax rule that treats a contractor invoicing through their own company as employed for tax. As of 17 August 2026, mutuality of obligation and a right of control are HMRC's pre-conditions. Beyond them, the terms of the engagement remain central. Medium and large clients with a UK connection decide, and carry the tax when wrong.

Do the Off-Payroll Working Rules Apply to You?

Two regimes share the name IR35, and only one of them puts a decision on your desk.

Chapter 8 of the Income Tax (Earnings and Pensions) Act 2003 arrived in April 2000. Under it, the worker's own intermediary assesses the engagement and operates PAYE and National Insurance where the rules bite. Nothing is asked of the engager.

Chapter 10, the off-payroll working rules, moved that duty to the client. It took effect for public authorities from 6 April 2017 and for medium and large clients outside the public sector from 6 April 2021. It applies to payments made on or after those dates, whatever date the work was done, and Chapter 8 stops applying once Chapter 10 does.

Both chapters need an intermediary. HMRC's condition is that the worker provides their services through their own intermediary, usually a limited company. A contractor who invoices you as a self-employed sole trader has no company in between, so neither chapter reaches that engagement. The working arrangements still get assessed, under the general employment status rules for tax, with no Status Determination Statement in the process. A mixed bench runs on two separate tracks.

Everyone says IR35. Only the second regime makes the decision yours.

How Does HMRC Decide Whether Your Contractor Is Really an Employee?

Take the intermediary out of the picture and ask what the relationship between you and the worker would be. That hypothetical contract is what the determination tests.

HMRC works through it in the structure the courts set in Ready Mixed Concrete, and the order carries weight. Mutuality of obligation and a right of control are necessary pre-conditions of employment. Mutuality means the engager must be obliged to pay a wage or other remuneration, and the worker must be obliged to provide their own work or skill. An overarching contract carrying no obligation to offer work does not by itself put a single engagement outside employment. Absent either pre-condition, the enquiry ends and the engagement sits outside IR35. Personal service sits in that first tier too. HMRC calls it an essential element of employment, and what matters is the right to provide a substitute rather than whether the worker ever exercises it. An engager with an unlimited right to veto substitutes may find the right was never genuine.

Clear the pre-conditions and the assessment turns multi-factorial. This is where inside and outside IR35 are actually settled. Mutuality and control return here to be weighed again, each of them just one of many factors that may be relevant, while the terms of the engagement with the end user remain central to the enquiry. HMRC's longer-standing framing asks the same thing from the other end: is the person performing the services doing so as a person in business on their own account? That draws the line between the individual who works under the control of and as part of the business of another, and the individual who goes it alone.

Which is why a contract template cannot answer it. A worker who serves you alone on a fixed schedule, inside your reporting line, on your equipment, with no real ability to send anyone else, looks like employment however the paperwork is headed. A worker with several clients, priced on output, carrying the cost of getting the work wrong, does not.

The individual factors get you into the evaluation. The whole picture decides it.

Does the IR35 Small Company Exemption Apply to Your Business?

Two sets of thresholds are live at once, and only one of them governs your off-payroll position.

The operative test, as at 17 August 2026, is the older one. A corporate client is medium or large if it meets at least two of these for two consecutive financial years: turnover above £10.2 million, a balance sheet total above £5.1 million, or an average of more than 50 employees. Size is fixed for the whole tax year rather than judged per engagement. Partnerships and other non-corporate undertakings use a simpler one-year test on turnover above £10.2 million.

The Companies Act thresholds did rise. From 6 April 2025 they moved to turnover above £15 million and a balance sheet total above £7.5 million, with the 50-employee limit unchanged, applying to financial years beginning on or after that date.

That change does not reach the off-payroll rules yet. HMRC's manual at ESM10006A, updated on 22 July 2026, states that for a normal 12-month financial year the earliest tax year the uplift can affect a client is 2027/28, because the earliest possible filing date for an accounting period beginning on or after 6 April 2025 falls in January 2027. Several advisory pages say the new figures reached off-payroll working on 6 April 2026 instead. HMRC's manual governs, and your position this year is governed by the £10.2 million and £5.1 million figures.

If you are small, the determination reverts to the contractor's own company under Chapter 8. One duty survives: on a formal request from the worker or from the party you contract with, you must confirm your size within 45 days, and a requestor who is ignored can apply to the courts for an injunction.

Reading next year's threshold as this year's is how a 60-person company talks itself out of a regime it is still inside.

Who Pays When the Status Determination Statement Is Wrong or Missing?

The Status Determination Statement is not administrative tidiness. It is the mechanism that transfers your liability.

An SDS carries the conclusion and the reasons behind it, and it has to have been reached with reasonable care. Reasonable care is conduct rather than a paragraph: HMRC weighs how you worked the hierarchy above, rather than what the document says about itself. Timing is the part that catches people. The statement has to be issued on or before the date any payment is made. Where payments go out before the SDS is issued, responsibility for the tax, National Insurance and apprenticeship levy remains with you.

HMRC's published examples make the inversion plain. A client reaches an "outside" determination with genuine care and never issues it, HMRC later disagrees, and the liability stays with the client. The same client reaches the same conclusion and issues it as an SDS, and the liability sits with the deemed employer instead. One document, two outcomes.

Reasonable care has named failure modes, and HMRC lists them. Deciding that every worker engaged through an intermediary is caught, without considering the individual engagement, is not reasonable care. Nor is entering inaccurate information into HMRC's CEST tool, leaving determinations to untrained staff, or failing to revisit a determination after the working arrangements materially change.

You also owe a response when a determination is challenged. Once a worker or deemed employer makes representations, you have 45 calendar days from receiving them to reply, counted from the representations rather than from your original statement.

Your determination protects you only once it has left your building.

How Far Up the Chain Can HMRC Reach?

The party that operates PAYE is the deemed employer, the lowest qualifying person in the contractual chain. Qualifying means UK resident or holding a UK place of business, which is why offshore parties cannot absorb the duty. Where a fee-payer sits offshore, the obligation rebounds to the nearest UK party above the worker, and handing the SDS to an offshore agency does not move responsibility away from the first UK agency in the chain.

Beyond that sits debt transfer. Where HMRC has pursued a deemed employer PAYE debt and sees no realistic prospect of collecting it, it can turn to a relevant person instead. The list of relevant persons is short: the first agency in the chain, and then the client. The order is fixed, agency one before you. Directors and officers are expressly out of reach, liabilities from tax years commencing before 6 April 2021 cannot be transferred, and HMRC must issue its recovery notice inside a 12-month window that opens 30 days after a regulation 80 notice, its formal PAYE assessment.

Set-off softens the arithmetic. For medium and large clients outside the public sector, where liabilities are assessed on or after 6 April 2024, HMRC applies set-off to deemed direct payments made on or after 6 April 2021 and accounts for tax the contractor and their company already paid. Income tax, corporation tax on the relevant profits, and employee, Class 2 and Class 4 National Insurance all count toward the offset. The employer's own secondary National Insurance contribution and the apprenticeship levy do not. Set-off shrinks the bill, and it leaves intact the two parts you cannot recover.

What Changed on 6 April 2026 for Umbrella Companies?

A new Chapter 11 took effect on 6 April 2026, covering any qualifying umbrella company payment made on or after that date. Earlier payments are untouched.

This is joint and several liability rather than the transfer mechanism the off-payroll rules use. Both parties are liable for the full amount, in whatever proportion, provided it is paid in full.

Chapter 11 engages only where an umbrella company employs the worker. A company contracting a contractor's own limited company direct has no umbrella in the chain and is outside this section entirely: the off-payroll rules above are the whole of its exposure.

Where there is an umbrella, the party on the hook alongside it is the agency holding the contract with the end client, and where you contract the umbrella directly, that party is you. HMRC states it plainly: the agency or end client is responsible for making sure PAYE is operated correctly when an umbrella company employs their workers, and HMRC can recover any underpayment from them. Existing supply chains are in scope alongside new ones, and HMRC frames the duty by position in the chain rather than by client size.

The definition follows function, not branding. An intermediary that employs the worker and carries on a business of supplying labour is covered whether or not it calls itself an umbrella company. Companies in which the worker holds a material interest above 5% are excluded.

Being outside the UK does not lift this. Where a worker is placed with a UK client by or through a non-UK resident agency, the client is jointly and severally liable alongside the umbrella company.

This is the one place where sitting outside the UK stops helping you.

Does Any of This Apply if Your Company Is Not in the UK?

For most US companies engaging a UK contractor, the honest answer is no, and the guidance is unusually direct about it.

A client is wholly outside the UK for Chapter 10 purposes if, and only if, immediately before the tax year begins it is not UK resident and has no UK permanent establishment. Wholly overseas clients do not need to consider the off-payroll working rules at all, and the worker's own intermediary considers Chapter 8 instead.

Permanent establishment takes its meaning from section 1141 of the Corporation Tax Act 2010. It covers a fixed place of business such as a branch, an office or a factory, and it also covers any agent who has, and habitually exercises, authority to do business on your behalf. That second limb is the one companies acquire without noticing.

Where a worker provides services to an offshore client through a UK resident intermediary, that intermediary is not a permanent establishment of the offshore client. Paying a UK contractor's limited company does not pull you into scope. Where an overseas client does have a UK permanent establishment, the duty belongs to the overseas entity itself, including issuing the SDS. The umbrella rules above are the exception.

What Does IR35 Not Decide?

Tax status and employment status are two systems, and IR35 settles only the first.

HMRC tells deemed employers plainly that the worker is not one of their employees, is not entitled to statutory payments or pension auto-enrolment, and is not entitled to employment rights from them such as holiday pay. A deemed employment for tax creates no rights against the engager.

Employment law then runs its own test. Its status categories decide the worker's rights and the employer's responsibilities, and a person may hold a different employment status in tax law than in employment law. Same working arrangements, different test, different forum. A tribunal claim for holiday pay or unfair dismissal is not answered by your SDS.

Winning the tax argument does not close the employment one.

What Do the IR35 Rules for Employers Require on an Ongoing Basis?

Seven obligations recur, and none of them is a one-off project.

Your size is assessed annually, because the rules fix it for the whole tax year. An SDS is required for every in-scope engagement before the first payment leaves, and a material change in working arrangements calls for a fresh determination. The 45-day disagreement clock runs whether or not anyone is watching it, which makes a named owner more use than a process document. Due diligence on the labour supply chain sits alongside all of it, and since April 2026 so does assurance that PAYE is operated correctly wherever an umbrella company employs your workers.

The seventh applies even to a company the rules do not otherwise reach. A formal request to confirm your size has to be answered inside 45 days, on its own clock, separate from the disagreement one. For a small company that request is the only piece of this it will ever have to action, and ignoring it is the one step here a court can be asked to compel.

The cost of skipping this is a matter of public record. The National Audit Office reported that the 2020-21 financial statements of government departments and agencies included £263 million paid, owed or expected to be owed in additional tax for failing to administer the reforms correctly. The recognised losses ran to £87.9 million at the Department for Work and Pensions and £72.0 million in total across the Ministry of Justice group. HMRC's own finding is the one that should concentrate attention: in all cases of non-compliance, it found the public body had not taken reasonable care to prevent errors, including when answering questions in the status tool.

Getting the paperwork right at onboarding costs far less than reconstructing it under enquiry. Our contractor onboarding checklist for global teams covers the classification and tax-form steps that build that trail, and our guide to hiring contractors in the United Kingdom gives the country-level snapshot, including the common risks and what is allowed when paying UK contractors in stablecoins. If you also employ people in the UK, paying UK staff in stablecoins is a separate exercise, with its own PAYE and real-time reporting duties.

Can You Rely on HMRC's CEST Tool?

HMRC will stand by the tool's result as long as the information you give it stays accurate and follows its guidance, which leaves the burden sitting on the quality of your inputs. HMRC updated CEST on 30 April 2025. Its estimate that the tool returned no determination in 15% of cases between March 2017 and October 2019, rising to 20% after the 2019 update, describes the versions that preceded that rebuild. A documented reasoning trail is what covers the engagements the tool cannot answer.

Reasonable care is the only part of this you fully control.

Toku provides compliance infrastructure and is not a law firm. This content is for informational purposes only and does not constitute legal or tax advice. Consult your legal counsel for jurisdiction-specific guidance.

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