Sorry for the delayed reply, I only check these once a week.

S 19 (1)(b) needs to be read in conjunction with s 19(1) "a worker means an individual". So 19 (1)(b) refers to an individual who is working as a contractor or subcontractor without an employer, otherwise they'd be captured by 19 (1)(c).

This creates the odd situation where if Anne Employee works directly as a contractor she can't be levied, but if she incorporates Upper Ltd (and is the sole director and employee), then Upper Ltd could be levied, so she's better off contracting as an individual.

"Person" and "individual" are distinct legal terms that only equivocate in one direction. An individual is a human being, so always a person. A person is a legal entity so not necessarily an individual, could be a company or even a river.