All workers on temporary visas (“migrant workers”) are entitled to the same minimum employment rights as any other workers in New Zealand. That means your employer must treat you fairly and provide you with minimum employment standards and a safe workplace.
This includes you having a written employment agreement and getting at least the minimum wage and four weeks’ annual holidays and all public holidays. Any deductions from your pay must be legal – like income tax or Kiwisaver. These minimum standards can be enforced by a government labour inspector. (See the chapter “Employment conditions and protections”.)
You can also take a personal grievance against your employer if you’re fired or treated unfairly, the same as any other worker can. (See the chapter “Resolving employment problems”.)
An employer that fails to comply with minimum standards may face a penalty and a set stand-down period from supporting further work visa applications.
If your visa says you must work for a specified employer, then you can’t change employers without applying to Immigration New Zealand for a change in your visa conditions.
Note: It’s illegal to do sex work if you’re in New Zealand on any kind of temporary visa.