""worker" means an individual who has entered into or works under (or, where the employment has ceased, worked under) – (a) a contract of employment; or (b) any other contract, whether express or implied and (if it is express) whether oral or in writing, whereby the individual undertakes to do or perform personally any work or services for another party to the contract whose status is not by virtue of the contract that of a client or customer of any profession or business undertaking carried on by the individual."
"The Employment Tribunal had also correctly concluded the applicants were not providing their services to the appellant company in the capacity of a "business undertaking" of which the company was a customer. The structure of limb (b) in reg. 2 (1) is that the definition extends prima facie to all contracts to perform personally any work or services but is then made subject to an exception relating to the carrying on of a "business undertaking"