Is your kitchen more than $5000? If so, a kitchen renovation company must legally be registered as a builder to supply your kitchen, as it is classified as building works in Victoria. This is also applied to bathrooom renovations.
Also, if your project is more than $16,000 (as most kitchens are) the registered builder must also provide you with the necessary Domestic Building Insurance to ensure that you are protected against losing any money you have paid in deposits, as well as giving you the peace of mind, that no matter what happens to the company you have employed, any issues you may experience will be rectified.
For more information please see the Victorian Building Authority website.