How to Find a Company's Federal Tax ID Number

Instructions
Finding Your Own Company's Federal Tax ID Number
1
Find the email or letter sent to you by the Internal Revenue Service (IRS) if you have misplaced the federal tax ID number for your business. You would have received this notice to confirm the receipt of your tax ID application with the IRS. On the confirmation form, typically in the top left corner, is your company's ID number.
2
Contact any bank or financial institution where you applied for a business account. To open one of these accounts, you had to give your company's ID number, and they may provide it to you on request.
3
Call the Internal Revenue Service's Business Tax Line at 1-800-829-4933. Request to speak to a federal tax assistant. He or she will ask you to provide identifiable corporate information that helps verify that you are indeed the owner of the business, and then provide you with your company's ID number.
Finding Your Employer's Federal Tax ID Number
1
Contact your company's human resources or accounting department. Some businesses, depending on their size, may combine the two departments. Request the company's federal tax ID number and explain why you need this information. Businesses are used to providing this information to employees and will give it to you for reasonable purposes.
2
Find an old W-2 form or similar tax or income record issued to you by the company. The business's federal tax ID number is often located on the sheet in the employer's information box.
3
Contact your local Internal Revenue Service office and ask to speak to a tax representative or assistant. They will provide the company's EIN.