Hi, I'm thinking of starting a small business. I have been told that I don't need and EIN number, that I can use my social security number, until my business is making a certain amount of money. However it has been my experience that the IRS requires an EIN number rather than a social security number, no matter how much one's business makes. If I start a business that is, for example, a temporary services agency, that makes very little money, do I need an EIN, or can I simply use my SS# to, for example, open my business checking account? If I can use my SS#, at what monetary level must I switch to an EIN for quarterly reporting to the US Gov.? You can be approximate in your answer. Thank you.