As a general rule, if your business is an entity other than a sole proprietorship (e.g., corporation, limited liability company, partnership), you will need a separate tax ID number for the entity. If you are a sole proprietor, you may use your social security number. Confim with a knowledgeable tax lawyer or CPA to determine what's right for your business.
Nina L. Kaufman, Esq. is an award-winning New York City attorney, edutainer and author. Under her Ask The Business Lawyer brand, she reaches thousands of entrepreneurs and small business owners with her legal services, professional speaking, information products, and LexAppeal weekly ezine. She also writes the Making It Legal blog.