Why do I have to pay Worker's Compensation for independent contractors ?

You only have to pay Worker's Compensation for independent contractors who do not have their own coverage of Workers Compensation insurance. They should provide a certificate of insurance to the "employer" to show evidence of their own coverage. Workers Compensation laws vary from state to state, but generally speaking these laws protect the employer as well as the worker. Anyone injured on the job will be covered and the employer is generally protected from lawsuits arising from injury on the job by an employee.