What outside IR35 means for contractors

A contract found outside IR35 is paid gross to the worker's company, which stays responsible for its own Income Tax and National Insurance ^[1]. Where a client makes that call and the worker disagrees, the client must respond to a formal challenge within 45 calendar days ^[2].

Being outside IR35 is the position most contractors want, because it means the engagement is treated as genuine self-employment for tax rather than disguised employment. It is not a status a contractor can simply claim. It follows from the facts of the engagement and, for medium and large clients, from a decision the client is required to make and record ^[3].

This guide explains what outside IR35 means, the tests that point to genuine self-employment, who is responsible for the decision, and what a contractor can do when a determination looks wrong. It reflects the position for the 2026-27 tax year.

Key takeaways

• Outside IR35 means the client has determined the worker would be self-employed for tax if engaged directly.
• An outside-IR35 fee is paid gross to the contractor's company, which accounts for its own tax under self-assessment.
• Status turns on real working practices, not on the presence of a limited company or the wording of a contract.
• Medium and large clients must issue a status determination statement and take reasonable care in reaching it.
• A contractor who disagrees can use the client-led disagreement process, which the client must answer within 45 calendar days.

What outside IR35 means

The off-payroll working rules ask a single question: would this worker have been an employee if they had contracted directly with the client, rather than through a company ^[4]. When the answer is no, the engagement is outside the rules. The worker is not a deemed employee, and payment for the work is made gross to the worker's intermediary ^[5].

That gross payment carries a responsibility with it. The contractor's company must account for its own Income Tax and National Insurance, and the individual settles any remaining liability through self-assessment ^[6]. Where a small business or an overseas client is the end client, the contractor's own company makes the status decision itself, rather than the client ^[7]. The full mechanics sit in the guide to the IR35 off-payroll working rules.

How a contract is judged outside the rules

Outside-IR35 status is decided by weighing several employment status factors together. No single point settles it, but a consistent picture of independence points away from employment ^[8].

The tests that point to genuine self-employment

Three factors carry the most weight. A genuine, unfettered right to send a substitute to do the work is one of the strongest indicators of self-employment, because an employee must give personal service ^[9]. A lack of mutuality of obligation, where the client is not bound to offer work and the worker is not bound to accept it, points the same way ^[10].

Beyond those, HMRC guidance highlights the marks of a business run on its own account. A contractor who has their own premises, uses their own equipment, employs others, carries financial risk, or works for a range of clients sits outside the scope of the rules ^[11]. The Moonworkers Instant Payslip Generator can produce a compliant record where such a business pays a director or an employee of its own.

Why working practices beat the written contract

A clean contract is not enough on its own. HMRC looks at the actual working relationship, and a written term is only accepted where it reflects how the engagement really runs ^[12]. A contract that grants a right of substitution the client would never allow in practice carries little weight.

This is why contractors are advised to keep the day-to-day reality aligned with genuine self-employment ^[13]. Where the substance matches the paperwork, an outside-IR35 arrangement stands up better to a later enquiry. The distinction between self-employment and employment for tax also shapes how the income is reported, a theme covered in the guide to PAYE and self-assessment.

Who decides, and how to challenge a wrong decision

For public-sector, medium, and large clients, the client is responsible for the status decision. The client must issue a status determination statement setting out the outcome and the reasons for it, and must take reasonable care in reaching it ^[14].

Reasonable care and blanket decisions

Reasonable care means acting as a prudent and reasonable person in the client's position would ^[15]. A client that applies a single determination across a group of workers with different terms, without considering each engagement, has not taken reasonable care, and HMRC does not accept such blanket decisions ^[16]. A contractor placed inside the rules by a blanket decision has a strong basis to challenge it.

The client-led disagreement process

A worker or a deemed employer who disagrees with a determination can use the client-led disagreement process. The client must consider the representations, keep the current tax treatment in place while it reviews, and respond within 45 calendar days ^[17]. If the client fails to respond in time, it becomes the deemed employer and takes on the tax liability itself ^[18].

If the worker still disagrees after that process, the route is self-assessment. The individual can reflect their own view of their status in a return after the end of the tax year, once tax has been accounted for ^[19]. Contractors running their own payroll for a small company should keep the determination and any correspondence on file.

Conclusion

Outside IR35 is less a badge to earn than a description of how an engagement actually works. A contractor who runs a real business, keeps genuine independence in the day-to-day work, and holds the paperwork to match will usually find the status follows naturally. The client's determination matters, but it has to be grounded in the facts, and a blanket decision that ignores them is open to challenge.

The safer position for any contractor is to treat status as something to evidence continuously rather than argue after the fact. Clear records, working practices that match the contract, and a prompt use of the disagreement process when a determination looks wrong are what keep an outside-IR35 engagement on solid ground.

Frequently asked questions

What does being outside IR35 actually mean for a contractor's pay?

It means the engagement is treated as genuine self-employment for tax. The fee is paid gross to the contractor's limited company or other intermediary, with no Income Tax or National Insurance deducted at source by the client. The company and the individual are then responsible for accounting for their own tax, typically through the company's payroll and the individual's self-assessment return.

Does a right of substitution guarantee an outside IR35 result?

No single factor guarantees the outcome, but a genuine and unfettered right to send a substitute is one of the strongest pointers to self-employment. The right has to be real. If the client would never accept anyone other than the named worker, a substitution clause in the contract carries little weight, because HMRC looks at the actual working relationship rather than the wording alone.

Who decides whether a contract is outside IR35?

For public-sector clients and medium or large private-sector clients, the client decides and must issue a status determination statement with its reasons. Where the end client is a small business or is wholly overseas, the contractor's own company makes the decision instead. In every case the decision must reflect the real terms and working practices of the engagement.

How can a contractor challenge a determination they think is wrong?

The contractor can use the client-led disagreement process, which requires the client to consider the representations and respond within 45 calendar days. The tax treatment stays as it is while the review runs. If the client misses the 45-day deadline, it becomes the deemed employer and liable for the tax. Where the contractor still disagrees afterwards, they can reflect their own view through self-assessment after the tax year ends.