One of the key responsibilities for many new businesses or businesses that are restructuring is obtaining an Employer Identification Number, or EIN, from the IRS. An EIN is a unique nine-digit number that identifies your business for tax purposes. It's similar to a Social Security number but is meant for business related items only.

An EIN also helps you register a business entity, obtain a business loan, open a business bank account and much more. An EIN is as important for your company as a Social Security number is in your personal life. For some businesses, an EIN is a tax requirement.

Do I need an EIN if I am self- employed? You don't need an EIN if you're self-employed; you can simply use your Social Security number. However, some people who are self-employed choose to apply for an EIN instead of using their Social Security number to reduce the risk of identity theft; it's less likely for someone to break into your accounts when you keep business finances and personal finances separate.

EINs must be used by business entities--corporations, partnerships, and limited liability companies. However, most sole proprietors don't need to obtain an EIN and can use their Social Security numbers instead.