A. Business Tax ID Number
A business tax ID number is required for all businesses. For example, Paul and Mary fall in love, get married and buy a house. Then they decide to start a business selling cangaroo backpacks from home. I.e., they start it with a website with a home office online from home. Thus, it is purely a home based business with an internet presence selling merchandise. In such a case, he will need to obtain the necessary licensing. One of these is a business tax ID that all businesses must have. If Paul and Mary decide to go into business as husband and wife or just as a sole proprietor, they must either obtain a federal tax ID number or use their social security number as a business tax ID number. If they will register the business as a partnership, LLC, or corporation, they must use the federal tax ID number as a business tax ID number. Thus, that would be their business tax ID number.