To conduct business within NY State:
For more information, please refer to Forming a Business in New York: An Overview.
Federal Employer ID Number (EIN)
Federal law requires corporations, partnerships, and certain sole proprietorships to have an Employer/Taxpayer Identification Number, or EIN. For more information, please refer to Do You Need an EIN?
The EIN is used to conduct business in New York City. No additional identifying number is required.
You can apply for an Employer Identification Number online or by using Federal Form SS-4. For more information, please refer to How to Apply for an EIN.