IR35 has been generating anxiety across the UK contractor market since its original introduction in 2000. The 2017 and 2021 reforms, which shifted responsibility for status determinations to medium and large clients, changed the landscape significantly. April 2026 introduces additional adjustments that modify the criteria for the off-payroll changes working rules to apply, along with the associated compliance requirements.
For tax advisors working with both individual clients and contractors, the ongoing issue with IR35 has consistently been the same. The rules are clear in their broad architecture and frequently unclear in their specific application. Status determination is a facts-and-circumstances analysis that does not produce obvious answers in the large majority of cases that sit in the middle ground between clearly employed and clearly self-employed. The 2026 changes do not simplify that analysis. They change who it applies to and under what conditions. This indicates that the number of firms and contractors impacted also changes.
This guide works through the IR35 framework for those newer to it, covers the specific April 2026 threshold and compliance changes, and addresses the practical steps that firms and contractors need to take now.
What is IR35 and Off-Payroll Working?
IR35 applies where an individual provides their services to a client through an intermediary, typically a personal service company, in circumstances where they would be regarded as an employee if engaged directly. Where IR35 applies, the income received through the intermediary is treated as employment income for tax purposes. PAYE and National Insurance apply. The tax efficiency that a PSC structure would otherwise provide is removed.
How to Analyse the Status Determination
Determining whether IR35 is applicable to a specific engagement involves a status assessment. This is an assessment of the working relationship against employment status tests established through case law.
- Mutual obligation pertains to the client’s responsibility to offer work and the worker’s obligation to accept it.
- Substitution: does the worker have a genuine right to send a substitute in their place, and would the client accept a substitute?
- Control: does the client control what work is done, how it is done, when it is done, and where it is done?
These three tests are not individually determinative. They are considered collectively, alongside other factors. The assessment is not mechanical. It requires professional judgement applied to the specific facts.
The Deemed Employee and the Tax Consequence
Where a status determination concludes that IR35 applies, the deemed employment payment rules apply. The fee income received by the PSC from the client is treated as employment income. The PSC must operate PAYE and account for employer and employee National Insurance contributions. The contractor loses the ability to extract income from the PSC in the more tax-efficient combination of small salary and dividends that characterises a legitimate outside-IR35 engagement.
The financial cost of being inside IR35 versus outside it, across a full year’s contracting income, is substantial. For a contractor generating £100,000 of fee income through a PSC, the additional tax and National Insurance cost of an inside-IR35 determination, compared with an outside-IR35 position, can exceed £20,000. The status determination is therefore not an administrative exercise, but rather a financial one.
The Off-Payroll Working Rules: How is Responsibility Allocated?
Since April 2017, the duty of determining status for public sector clients has transferred from the contractor’s PSC to the final client. This change also affects medium and large private sector clients starting from April 2021.
The Current Client Responsibility Framework
Under the off-payroll working rules, the end client must make a Status Determination Statement for each contractor engagement. The SDS must reach a reasoned conclusion on status and must be provided to the contractor and to the fee-payer (typically the recruitment agency or staffing company through whom the contractor is engaged). The fee-payer then operates PAYE on the fees if the determination is inside IR35.
The end client carries the tax risk if the SDS is issued without reasonable care. Where HMRC concludes that a status determination was incorrect and that the engagement was inside IR35, the liability for the unpaid PAYE and NIC falls on the client. Reasonable care must be demonstrated through a documented, thorough, and consistent status determination process.
The Small Company Exemption
The off-payroll working rules do not apply where the end client is a small company. The small company definition for this purpose uses the Companies Act 2006 criteria: turnover below £10.2 million, balance sheet below £5.1 million, and fewer than 50 employees. A company that meets two of these three conditions is small.
When the end client is small, responsibility for the status determination reverts to the contractor’s PSC. The contractor assesses their own status and accounts for any IR35 liability accordingly. The 2026 threshold changes affect this exemption in a way that materially changes which clients are in scope.
IR35 Regulations in the UK: Anticipated Changes for 2026 and Their Justifications
The off-payroll working rules IR35 threshold changes for 2026 reflect the government’s continued effort to close the compliance gap in the contractor market while avoiding the chilling effect on flexible working that overly broad application of the rules creates.
The Small Company Threshold Adjustment
From April 2026, the small company threshold criteria used to determine whether the off-payroll working rules apply to an end client are being updated. The turnover and balance sheet thresholds are being uplifted to reflect inflation and the changed economic environment. The £10.2 million turnover threshold and £5.1 million balance sheet threshold have not been materially revised since their introduction. This is despite the significant changes in the cost base of UK businesses since 2021.
The turnover limit will increase to £15 million, and the balance sheet threshold will be raised to £7.5 million starting April 2026. The employee headcount condition of fewer than 50 employees remains unchanged.
The practical consequence of this change is that some businesses found themselves caught within the off-payroll working rules. This includes businesses with turnover between £10.2 million and £15 million. Henceforth, will now fall below the new small company threshold. For those businesses, responsibility for status determinations reverts to the contractor’s PSC from April 2026. The administrative burden of producing SDSs for every contractor engagement shifts back to the contractor rather than sitting with the client.
Businesses Moving Out of Scope
For HR and finance teams at businesses in the £10 to £15 million turnover band who have been operating a full SDS process since 2021, the April 2026 change is operationally significant. The compliance infrastructure they have built will no longer be required for engagements that begin on or after April 6, 2026.
The transition is not automatic. Engagements in progress on April 5, 2026, that are inside IR35 under a current SDS continue under that determination until the engagement ends or a new SDS is issued. The threshold change affects new engagements and renewals from April 6. However, it does not retrospectively alter the status of existing engagements.
The Compliance Enhancement Changes
Alongside the threshold adjustment, April 2026 brings enhanced HMRC compliance activity targeting IR35 non-compliance in specific sectors. HMRC’s IR35 compliance teams have historically concentrated activity on the IT contractor market, the financial services sector, and the public sector. Essentially areas where off-payroll working is most prevalent and where the compliance gap has been most significant.
From April 2026, HMRC is extending its compliance focus to the construction sector. This is where the interaction between CIS and IR35 creates compliance complexity. This also includes the professional services sector, where the distinction between genuinely self-employed consultants and disguised employees is frequently unclear.
The Check Employment Status for Tax Tool
HMRC’s CEST tool is being updated alongside the April 2026 changes to reflect the revised case law position on the key status factors. The tool has been criticised since its introduction for producing determinations that do not adequately reflect the nuances of real-world working arrangements. The 2026 update addresses several specific areas where the tool’s outputs have been challenged. This includes, notably the treatment of the right of substitution and the mutuality of obligation test.
For clients and contractors relying on CEST to support their status determinations, the update is relevant to all new determinations from April 2026. Existing determinations made before April 6, 2026, should be reviewed against the updated tool where the engagement continues beyond that date.
Practical Status Determination: What Reasonable Care Looks Like
The reasonable care standard is the compliance test that determines whether an end client escapes liability for incorrect status determinations. Understanding what reasonable care means in practice is essential for clients maintaining SDS processes under the off-payroll working rules.
The SDS Process That Demonstrates Reasonable Care
A status determination process that demonstrates reasonable care is documented, consistent, and based on genuine engagement with the facts of each contractor relationship. It is not a tick-box exercise applied uniformly across all contractors. It is not a blanket determination without individual assessment. Both approaches fail the reasonable care test.
The documentation that supports a reasonable care defence includes:
- Information gathered from the contractor and the hiring manager about the working arrangement
- Analysis of that information against the relevant employment status tests
- Conclusions reached on each of the key factors and the overall status conclusion
- Communication of the SDS to the contractor and fee-payer
That documentation needs to exist for every engagement. Verbal determinations, informal discussions, or a generic assessment applied to groups of contractors without individual review do not satisfy the reasonable care standard.
When the Determination Should Be Reviewed
A status determination is not a permanent position. Changes in the working relationship can alter the status conclusion. A contractor who begins an engagement working on client premises may move to a position of working remotely with greater autonomy.
The SDS should be reviewed when the working arrangement changes materially, when the engagement is renewed on different terms, and at regular intervals for long-running engagements. A status determination made three years ago that has never been reviewed is not a status determination that demonstrates current reasonable care.
IR35 and the Contractor’s Perspective
For contractors operating through PSCs, the April 2026 changes have a different significance depending on whether their clients are moving below or remaining above the adjusted small company threshold.
Contractors Whose Clients Move Below the Threshold
A contractor whose end client had turnover between £10 million and £15 million will find that from April 2026, responsibility for their status determination reverts to them. The client will no longer be required to issue an SDS for new engagements. The contractor’s PSC is responsible for assessing its own IR35 status and accounting for any resulting liability.
For contractors who have been working under an inside-IR35 determination, the reversion of responsibility creates an opportunity to reassess the status position. This is based on the actual working arrangement where genuine facts support an outside-IR35 conclusion. The contractor can operate outside IR35 from April 2026 without the override of a client SDS.
Contractors Seeking Outside-IR35 Engagements
For contractors seeking new engagements that are genuinely outside IR35, the April 2026 environment creates some additional opportunity. The increased small company threshold means more clients fall below the off-payroll working rules, reducing the administrative burden on clients of engaging outside-IR35 contractors. Some clients previously avoiding contractor engagements because of SDS administration will find the threshold change removes that barrier.
The outside-IR35 case still needs to be genuine. The working arrangement needs to reflect genuine self-employment like real substitution rights, limited control, and genuine economic risk. A contractor whose working arrangement is indistinguishable from employment does not become outside IR35 because the threshold change means the client no longer issues an SDS.
IR35 Compliance Outsourcing: The Case for Specialist Support
The complexity of IR35 status determination and the financial consequences of getting it wrong can be severe. This makes it one of the clearest candidates for specialist outsourced compliance support, both for end clients maintaining SDS processes and for accountants advising contractor clients.
What IR35 Compliance Outsourcing Covers
IR35 compliance outsourcing for end clients covers the design and implementation of the SDS process, the individual assessment of contractor engagements against the employment status tests, the preparation and communication of SDSs to contractors and fee-payers, the documentation of the reasonable care evidence trail, and the ongoing monitoring and review of existing determinations.
For accounting firms advising contractor clients, IR35 compliance outsourcing covers status determination reviews, IR35 contract reviews, PSC accounting that correctly reflects the inside or outside-IR35 position, and representation in HMRC compliance checks where the contractor’s status is under enquiry.
The Threshold Change as a Review Trigger
The April 2026 threshold changes provide a natural review point for both clients and contractors. For clients moving below the new threshold, the review question is whether the infrastructure built for off-payroll working is still needed and how to manage the transition correctly. For contractors, it is whether the status position of existing engagements needs to be reassessed in light of the changed responsibility landscape.
For accounting firms and tax consultants, the April 2026 changes generate a specific client communication and review opportunity. One that positions the practice as proactively managing the change rather than responding to it after the fact.
What Firms and Contractors Need to Do After April 2026
The preparation steps are specific and time-bound. Leaving them to the final weeks before April 6 creates the same compressed-timeline risk that every regulatory change produces when preparation is deferred.
The Action List for End Clients
Review current contractor headcount against the updated threshold criteria. Businesses with turnover approaching or straddling the £15 million threshold need to confirm their position with reference to the balance sheet and headcount tests as well as turnover. The two-of-three test means turnover alone does not determine the outcome.
Review existing SDSs for engagements running beyond April 6, 2026. The threshold change does not retroactively alter existing SDS determinations, but where a client is moving below the threshold, new engagements and renewals from April 6 will not require a client SDS. The transition process needs to be planned and executed.
Update the CEST-based determination process to reflect the April 2026 tool update. Determinations for new engagements from April 6 should be made using the updated tool.
The Action List for Contractors
Identify which clients are likely to move below the new threshold. For contractors with multiple concurrent engagements, some clients may remain above the threshold while others fall below it. This creates a mixed position where some engagements continue under client SDSs, and others revert to PSC responsibility.
Review the IR35 position for engagements where responsibility is reverting to the PSC. A status determination that was made by the client may not reflect the genuine facts of the working arrangement. An independent assessment of the actual working relationship may reach a different conclusion.
Review IR35 contracts. The contractual terms of the engagement are one input into the status determination. Contracts that include blanket outside-IR35 clauses without reflecting the genuine working arrangement carry risk. Contracts that accurately reflect the key status factors provide a stronger foundation for an outside-IR35 position.
