EIN stands for Employee Identification Number.
Depending on how your business is registered with the IRS your business may have an Employee Identification Number.
Typically businesses that are registered as an LLC, corporation, or partnership have an EIN.
Sometimes businesses that are registered as sole proprietors can also have an EIN.
This is NOT the same thing as your social security number.
Only if you're sure that your business has an EIN go through the "YES" path in the flowchart.
If you file your business's taxes to with your social security number, please go through the "NO" path.