Also known as a Federal Tax Identification Number (TIN), an Employer Identification Number (EIN) is used to identify a business entity. Generally, businesses need an EIN.
Where can I find the EIN?
The EIN is a 9-digit number, with a dash separating the first 2 digits: XX-XXXXXXX.
Your employer’s EIN is located in box b of your W-2 form, right above your employer’s name and address.
On most 1099 forms the EIN is located in the box just below the Payer's name and address, on the left side of the form.