Outside IR35 meaning: what it is and who pays tax

When an engagement is outside IR35, the fee is paid gross to the contractor's own company with no Income Tax or National Insurance deducted at source ^[1]. That is the opposite of an inside determination, where the fee-payer deducts PAYE and pays employer National Insurance at 15% for the 2026-27 tax year ^[15]. The difference decides how a contractor is taxed, so the meaning of outside IR35 is worth pinning down precisely.

This guide explains what outside IR35 means, the status factors that place an engagement there, the small-client exemption, and who then carries the tax responsibility.

Key takeaways

• Outside IR35 means the worker is self-employed for tax on that engagement, so the fee is paid gross ^[1].
• The contractor's own company then accounts for tax through Corporation Tax and Self Assessment, not through the client's payroll ^[4].
• A right of genuine substitution, control over how the work is done and business risk all point outside the rules ^[10].
• If the end client is small, the off-payroll rules do not apply and status is decided by the worker's own intermediary ^[1].
• A small client is defined by the Companies Act size test, based on turnover, balance sheet total and employee numbers ^[13].

What outside IR35 means

The off-payroll working rules exist to make a worker who provides services through their own intermediary pay broadly the same Income Tax and National Insurance as a directly engaged employee ^[1]. An engagement is outside those rules when the client decides the worker would be self-employed for tax if they were engaged directly ^[1].

When that is the case, the worker is not a deemed employee, and any remuneration for the engagement is paid gross to the intermediary ^[1]. HMRC describes this as being outside the off-payroll working rules ^[1]. Individuals who run a genuine business, for example working for a wide range of clients, employing others or holding their own premises, sit outside the scope and account for tax through Corporation Tax Self Assessment and Income Tax Self Assessment ^[1].

Outside IR35 is therefore a statement about the working reality, not a label a contractor can simply choose ^[5]. Contractors who invoice several clients often rely on a one-off HMRC-compliant payslip when they do take a salary from their own company, separately from any engagement fee.

What places an engagement outside IR35

Status turns on the same employment tests whether the answer is inside or outside. The factors that push an engagement outside are those that make the worker look like a business rather than an employee.

Substitution and control

A genuine right to send a substitute is a strong pointer away from employment, because a contract for personal service is a hallmark of employment ^[10]. Where the client cannot insist on one named individual and the worker can supply a qualified replacement, that undermines the personal-service feature ^[10]. Control matters too: a worker who decides how, and often when and where, the work is done, rather than being directed by the client, resembles a self-employed contractor ^[12].

Mutuality of obligation and business risk

Mutuality of obligation asks whether the engager must offer work and the worker must accept it ^[9]. A contractor engaged for a defined deliverable, free to decline further work and carrying the financial risk of correcting defects at their own cost, looks like a business on their own account ^[12]. HMRC's Check Employment Status for Tax tool weighs these same factors, and its result can be saved as a status determination statement ^[11].

The small-client exemption

There is a second, entirely separate route to being outside the rules that has nothing to do with the working arrangement: the size of the client ^[1].

An engagement is outside the scope of the off-payroll rules if the end client is small ^[1]. In that case, responsibility for deciding status shifts back to the worker's own intermediary, which applies the original IR35 rules itself ^[1]. A corporate client is medium or large, and so within scope, if it meets at least two size criteria across two consecutive financial years ^[13]. The three criteria come from the Companies Act size test.

Meeting two of the three across two consecutive years moves a company between small and medium or large ^[13]. Where the client is small, the worker's intermediary keeps the status decision, so the contractor cannot assume gross payment means the arrangement is genuinely outside on its facts ^[4]. Bureaux supporting contractor companies often centralise this in a payroll bureau platform.

Who pays the tax when outside IR35

Outside the rules, the client and fee-payer make no deductions from the engagement fee ^[4]. They also owe no employer National Insurance or Apprenticeship Levy on that payment ^[4]. The contractor's company receives the fee gross and settles its own tax: Corporation Tax on profits, then Income Tax and National Insurance on any salary the worker draws, plus tax on dividends ^[1].

Getting the determination right matters to both sides, because HMRC publishes a specific method for calculating PAYE liability where the rules should have applied but did not ^[14]. A contractor who does take a salary from their own company runs it through HMRC-recognised payroll software, and platforms serving contractor accountants can automate that through an HMRC-recognised payroll API. The mechanics of the deemed-employment alternative are set out in the overview of IR35 and off-payroll working.

Conclusion

Outside IR35 means an engagement sits beyond the off-payroll rules, so the fee is paid gross and the contractor's own company shoulders the tax. That can be because the working reality is genuinely one of self-employment, judged on substitution, control and business risk, or because the end client is small and the rules simply do not bite.

Either way, the label is earned by facts rather than chosen for convenience. A contractor and client who document the substitution rights, control and risk that place an engagement outside, and who understand which party carries the status decision, are far better placed if HMRC later asks how the conclusion was reached.

Frequently asked questions

What does outside IR35 mean for a contractor's take-home pay?

Outside IR35, the engagement fee is paid gross into the contractor's company with no tax deducted at source ^[1]. The company then pays Corporation Tax on its profit, and the worker pays Income Tax and National Insurance on any salary and tax on dividends drawn ^[1]. This usually leaves more flexibility over how and when income is taken than an inside determination allows.

Does a small client mean an engagement is automatically outside IR35?

Not quite. If the end client is small, the off-payroll rules do not apply, but the worker's own intermediary must then decide status under the original IR35 rules ^[1]. So gross payment by a small client does not confirm the engagement is genuinely outside on its facts; the contractor still needs the working arrangement to support that position ^[4].

How is a client's size decided for IR35?

A company is medium or large, and so within the rules, if it meets at least two of three Companies Act criteria, turnover, balance sheet total and average employee numbers, across two consecutive financial years ^[13]. The employee count includes only those directly employed, not deemed employees ^[13]. A company crosses the boundary only after the test is met for two years running.

Can the same contractor be inside IR35 on one contract and outside on another?

Yes. Status is decided engagement by engagement, on the working arrangement for each contract ^[5]. A contractor can hold one engagement that is inside because it looks like employment and another that is outside because it carries genuine substitution rights and business risk ^[10]. Each engagement needs its own status decision.