Will IR35 apply to all contractors?

IR35 does not apply to all contractors.

To determine if IR35 applies, the IR35 status needs to be assessed. The onus for determining the status along with the tax liability depends on the size of the company to which the worker is providing their services.

Where the client is a medium or large company, the off-payroll working rules apply and that company is responsible for assessing the IR35 status of their workers. Once the company has determined the IR35 status, the worker must be informed of their IR35 position. This will either be that they are working "inside IR35" (subject to the legislation) or "outside IR35" (not subject to the legislation).

Contractors working for small companies in the private sector are responsible for assessing their own IR35 status and must process their taxes according to the IR35 status they conclude.

If the contractor's engagement meets the criteria for being an employee, IR35 will apply. But if the contractor is deemed genuinely self-employed, IR35 will not apply, and they will be considered "outside IR35".