IT Contractor IR35 Agreement Template UK
Navigating IR35 status uncertainty is one of the biggest challenges facing UK IT contractors operating through a Personal Service Company. Without a properly drafted contract, HMRC may determine that your engagement falls inside IR35 under Chapter 10 of the Income Tax (Earnings and Pensions) Act 2003, exposing you to significant backdated tax liabilities. A well-structured IR35 agreement establishes the commercial and contractual reality of your working arrangement, clearly demonstrating substitution rights, lack of mutuality of obligation, and genuine financial risk — the three pillars HMRC and the courts use to assess employment status. Whether you are contracting directly with a client or through a recruiter, having the right contract language in place is your first line of defence. Generate your compliant IT Contractor IR35 Agreement now and protect your outside-IR35 status today.
Generate your IR35 Agreement free →Key clauses in a IR35 Agreement
Right of Substitution
This clause establishes that the contractor retains the genuine right to send a qualified substitute to perform the services in their place, without requiring the client's approval based on personal preference. Substitution rights are a critical indicator of self-employment under the HMRC IR35 tests and were central to the Supreme Court's reasoning in Pimlico Plumbers v Smith [2018], making this clause essential for demonstrating an outside-IR35 position.
Mutuality of Obligation
This clause explicitly states that the client is under no obligation to offer work and the contractor is under no obligation to accept it, negating the continuous employment relationship that HMRC looks for under Chapter 10 of ITEPA 2003. Without this clause, an ongoing engagement could imply an irreducible minimum of mutual obligation, which tribunals such as the Court of Appeal in Usetech Ltd v Young [2004] have identified as pointing towards deemed employment.
Financial Risk and Equipment
This clause confirms that the contractor bears genuine financial risk, including responsibility for correcting defective work at their own cost and providing their own equipment and tools to perform the services. HMRC's Check Employment Status for Tax (CEST) tool and case law consistently treat financial risk and the provision of one's own equipment as strong indicators of a business-to-business relationship sitting outside IR35.
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Generate free →Frequently asked questions
Does having an outside-IR35 contract automatically protect me from HMRC investigation?
A well-drafted contract is necessary but not sufficient on its own — HMRC will look beyond the written terms to assess the actual working practices under Chapter 10 of ITEPA 2003. If the day-to-day reality of your engagement contradicts what the contract says, for example if you cannot truly substitute or must work set hours on-site, HMRC can disregard the contractual language. Your contract must accurately reflect how you genuinely operate to provide meaningful protection.
Who is responsible for IR35 status determinations since the off-payroll working rules changed in April 2021?
Since the off-payroll working reforms took effect in April 2021 under Chapter 10 of ITEPA 2003, the responsibility for making a Status Determination Statement (SDS) shifted to the end client in medium and large private sector engagements. The client must issue a written SDS to the contractor and the fee-payer, and the contractor has the right to formally dispute a determination they believe is incorrect through the client-led disagreement process.
Can I use a contract template for both inside and outside IR35 engagements?
No — inside and outside IR35 contracts require fundamentally different drafting because they reflect entirely different commercial and tax arrangements. An inside-IR35 engagement means the fee-payer deducts income tax and National Insurance Contributions at source before paying your PSC, whereas an outside-IR35 contract should contain clauses such as substitution, financial risk, and absence of mutuality that positively support self-employment status under HMRC guidance. Using the wrong template could create contractual inconsistencies that weaken your IR35 position.
The information on this page is for general informational purposes only and does not constitute legal advice. Contracto generates AI-assisted contract templates — they are not a substitute for advice from a qualified solicitor. For high-value or complex engagements, always seek independent legal review.