The Construction Industry Scheme (CIS) is a UK government tax scheme that applies to workers in the construction industry. The purpose of the CIS is to ensure that the correct tax and National Insurance contributions are paid on construction work.

Under the CIS, workers in the construction industry are divided into two categories: CIS deductions workers and CIS non-deductions workers. CIS deductions workers are employees or workers who are paid gross and have tax and National Insurance contributions deducted from their pay, while CIS non-deductions workers are self-employed and are responsible for their own tax and National Insurance contributions.

The CIS applies to contractors and subcontractors in the construction industry, and it sets out rules for the payment and reporting of tax and National Insurance contributions. It is important for workers and contractors in the construction industry to understand the CIS rules and to ensure that the correct tax and National Insurance contributions are paid.