Employee vs Contractor

The distinction between an employee and a self-employed contractor is one of the most important and contested areas of UK tax law. Getting it wrong can result in significant back-tax bills, National Insurance contributions, penalties, and interest. HMRC uses a combination of case law tests and statutory rules to determine employment status, and the consequences extend beyond tax — they affect employment rights, holiday pay, sick pay, and pension entitlements. This guide covers the key tests, the IR35 and off-payroll rules, and practical steps to manage status risk.

Employment Status Tests

HMRC and employment tribunals determine status by applying a series of common-law tests developed through court decisions. The three core tests are: control (does the engager control what, when, and how the work is done?), substitution (can the worker send a substitute?), and mutuality of obligation (is the engager obliged to provide work, and the worker obliged to accept it?). In practice, a tribunal looks at the whole picture — written contract wording is relevant but can be overridden by how the arrangement operates in reality. Other factors include whether the worker provides their own equipment, bears financial risk, has the opportunity to profit from sound management, and is integrated into the engager's business. If most of these indicators point to independence, the worker is likely self-employed.

IR35 — The Intermediaries Legislation

IR35 applies when a worker provides their services through an intermediary — typically their own limited company — but would be an employee if engaged directly. Where IR35 applies, the intermediary must pay tax and NIC on the deemed employment payment as if the worker were an employee. For 2025/26, deemed employment income is subject to employee NIC and employer NIC, plus Income Tax via PAYE. The intermediary loses its Corporation Tax deduction on the deemed payment. IR35 does not apply if the worker is genuinely in business on their own account. The key defence is a robust, compliant contract that reflects the actual working practices and passes the status tests above.

Off-Payroll Working Rules (Chapter 10 ITEPA 2003)

Since April 2021, medium and large clients in the private sector are responsible for determining the IR35 status of engagements (the off-payroll working rules). A client is medium or large if it meets two of these three criteria: annual turnover over £10.2 million, balance sheet over £5.1 million, or more than 50 employees. Small clients are exempt — the responsibility stays with the worker's intermediary. If the client determines that the engagement is caught by IR35, it must deduct PAYE and NIC from the fees paid and account for them to HMRC. The worker's intermediary no longer accounts for tax on the deemed payment. The fee-payer (usually the client or agency) is responsible for operating PAYE. HMRC's CEST (Check Employment Status for Tax) tool provides a determination, but its accuracy is limited for complex cases — many advisers recommend a bespoke status review alongside CEST.

Worker Rights Differences

The employment status classification has major implications for rights. Employees have the fullest rights: statutory sick pay, minimum notice periods, protection against unfair dismissal, redundancy pay, parental leave, and the right to request flexible working. Workers (a broader category that includes casual workers and some contractors) have fewer rights: the National Minimum Wage, paid holiday, rest breaks, and protection against discrimination. Self-employed contractors have no employment rights from the engager — they are in business on their own account and must arrange their own insurance, pension, and benefits. The tax status (employed vs self-employed for HMRC) is separate from employment status (employee vs worker vs self-employed for employment law), but they often align in practice.

Practical Steps for Businesses

If you engage contractors, conduct a status review for each engagement. Document the reasons for your determination, keep the contract and working practice evidence, and reassess when the engagement changes. If your organisation is medium or large and you engage contractors through their own limited companies, implement a robust off-payroll determination process and issue a Status Determination Statement (SDS) to the worker and the next party in the chain. Consider using a professional indemnity insurance policy that covers IR35 enquiry costs. For contractors concerned about IR35, consider operating through an umbrella company, although ensure the umbrella itself is compliant.

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