IR35 Construction Contractor Agreement Template UK
Operating as a construction contractor through a Personal Service Company exposes you to serious IR35 misclassification risk, particularly since the Off-Payroll Working reforms shifted liability to medium and large engagers under Chapter 10 of the Income Tax (Earnings and Pensions) Act 2003. Without a carefully drafted contract, HMRC can argue your working arrangement resembles employment, triggering unexpected tax and National Insurance liabilities for you or your client. A robust IR35 Construction Contractor Agreement documents genuine substitution rights, control boundaries, and financial risk — the three pillars HMRC scrutinises most heavily on construction sites. It also protects payment terms under the Late Payment of Commercial Debts Act 1998 and aligns with Construction Act adjudication rights. Protect your outside-IR35 status and your income today — generate a compliant construction contractor agreement now.
Generate your IR35 Agreement free →Key clauses in a IR35 Agreement
Right of Substitution
This clause establishes the contractor's genuine right to send a suitably qualified substitute to complete the services without requiring the client's personal approval, which is a key indicator of self-employment under HMRC's IR35 assessment framework. A credible, unrestricted substitution right is one of the strongest defences against HMRC reclassifying the engagement as employment under Chapter 10 ITEPA 2003.
Control and Direction Limits
This clause defines the boundaries of client supervision, specifying that the contractor determines how, when, and where the services are performed, rather than being directed like an employee — a critical distinction examined in IR35 cases such as Autoclenz Ltd v Belcher [2011]. Clearly limiting control in a construction context, where site attendance may be required, helps demonstrate the contractor operates as an independent business rather than an integrated worker.
Contractor Financial Risk
This clause requires the contractor to bear their own costs for equipment, insurance, and rectification of defective work, demonstrating genuine financial risk consistent with running a business — a mutuality-of-obligation test factor HMRC applies when determining IR35 status. Documenting financial exposure is particularly important in construction engagements where tools, plant, and professional indemnity insurance represent substantial contractor-borne expenditure.
Generate your IR35 Agreement in 2 minutes
AI-powered. Jurisdiction-aware. No account required for your first contract.
Generate free →Frequently asked questions
Who is responsible for issuing an IR35 Status Determination Statement on a construction project?
Since the April 2021 Off-Payroll Working reforms, medium and large private-sector clients are responsible for issuing a written Status Determination Statement (SDS) before the contractor begins work, under Chapter 10 ITEPA 2003. If the end client is a small company as defined by the Companies Act 2006, responsibility for determining and paying IR35 taxes remains with the contractor's PSC. Always obtain the SDS in writing and keep it with your contract documentation.
Does working on a CIS-registered construction site affect my IR35 status?
Being registered under the Construction Industry Scheme (CIS) and having tax deducted at source does not automatically place you outside IR35, nor does it confirm employment status — HMRC treats CIS and IR35 as entirely separate regimes. Your IR35 status is still determined by the real working arrangements, including control, substitution, and mutuality of obligation, regardless of how payments are processed under CIS. It is therefore essential that your contract accurately reflects how you genuinely operate on site.
Can I challenge an inside-IR35 determination made by a construction client?
Yes — under the Off-Payroll Working rules, contractors have a statutory right to use the client-led disagreement process to formally challenge an SDS they believe is incorrect, and the client must respond within 45 days. You should submit your challenge in writing, supported by evidence from your contract and actual working practices, referencing HMRC's Check Employment Status for Tax (CEST) tool output where favourable. If the client fails to respond in time, liability for unpaid tax can transfer back to them under the fee-payer rules in Chapter 10 ITEPA 2003.
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.