There are not any income thresholds before one can form a corporation.

Those who want to decrease their legal risk.

Those who hire your services may insist that you incorporate a company. If a company pays you as an independent contractor, there is a risk that IRS may deem that you are actually an employee. If this happens, the company that hired your services runs the risk of paying severe penalties if they did not withhold payroll taxes. Therefore, it is less risky for those who want to hire you. A 1099 form is required for an independent contractor. This form is not required for those who hire a corporation.

Those who want to raise money for a business venture.

Owning investment real estate in a properly structured corporation, limited liability company or limited partnership may provide tax and liability protection benefits.

Any person over the age of 18 can form a corporation.