IR35 legislation determines whether a contractor is genuinely self-employed or should be classed as an employee for tax purposes.
If HMRC decides your contract falls inside IR35, you could face higher tax and National Insurance contributions, leaving you with a reduced take-home pay.
This area has become more complicated in recent years, with the off-payroll working rules now shifting responsibility for IR35 compliance onto businesses in many cases.
Whether you’re a contractor or a business engaging contractors, mistakes can cause serious issues.

