When considering whether a person providing services to a business is an independent contractor or an employee, government agencies are going to look at a number of factors. No one factor is necessarily more important than another, but one that they will likely look at is: “The extent to which the services rendered are an integral part of your business”.
For example if you are an architecture firm and you hire an architect, that architect is rendering services that are an integral part of your business. Your business exists to deliver architectural designs, drawings, and plans for buildings. That’s what the architect is doing. For that reason, that probably is an employee and not a contractor.
An accountant working for an accounting firm would be rendering services that are an integral part of the business. The business exists to help their clients with their taxes, financial records, and financial management. That’s what the accountant would be doing.
However, an accountant working for a company that makes widgets would not be rendering services that are an integral part of the business. That business exists to manufacture and sell widgets and expand their market share in the widget world. An accountant, while important and perhaps even necessary, would be a back-lines role in that business. They are not actively engaged in delivering the products or services the company exists to deliver.
For that reason, the widget company could most likely hire an accountant as an independent contractor.
When you hire someone to work directly on the products or services your company exists to deliver, the company is going to face challenges when classifying that person as an independent contractor.