An individual who has entered into or works under:
A contract of employment (www.practicallaw.com/5-200-3117); or
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.
(Section 230(3), ERA 1996 (www.practicallaw.com/4-200-3207).)
For more information, see Practice note, Employment status: Worker status.