Engineering COA requirements

[rockman7892]

I'm trying to understand the requirement's for when a Certificate of Authorization (COA) is required to perform engineering work either as a solo enterprise or part of a large corporation. I understand that different states have different requirements for when this is required however I'm trying to get a basic general comprehension as to when this COA is required as part of performing engineering services.

Is this COA required anytime you are performing any type of engineering work (design, studies, consulting, etc...)as part of a solo enterprise, or is it only required when providing particular types of engineering services?

Similarly as part of a larger business or corporation is it required anytime you perform any type of engineering services? Does the requirement vary dependent on weather the corporation is an OEM, consultant, or other? I understand the requirements are more stringent for corporations.

Thanks