When starting a new business you will need to get a Federal Tax ID number to file your business tax returns unless you are a sole proprietor with no employees and you will not be filing any excise or pension plan tax returns. In that case you can file your business taxes using your social security number.
A Federal Tax ID number is a nine-digit number of the form XX-XXXXXXX. It is also referred to as a Taxpayer ID Number (TIN) or an Employer ID Number (EIN). The IRS uses all three designations interchangeably.
How to Apply for a Federal Tax ID Number
The IRS offers a number of ways to apply for a TIN.
By Telephone: You can call the Business & Specialty Tax Line at 800-829-4933 from 7am to 10pm, Monday through Friday. The federal tax ID number assigned to you over the phone and can be used immediately.
By Fax: Complete IRS Form SS-4 and send it to your state fax number, which can be found at Where to File - Business Forms and Filing Addresses. If you include your fax number on the form, the federal tax ID number will be faxed back within four business days.
By Mail: Complete IRS Form SS-4 and mail it in. You will receive your tax ID number within four weeks.
Online: You can use the Internet EIN application to give your information over the Internet, and a number will be issued to you once the information has been verified. Note that not all business types can use this method of application.
For faxed and mailed applications, if you have not received your confirmation notice within the time frame listed, call the Business & Specialty Tax Line listed above and ask about the status of your application. Do not reapply as you might be issued duplicate identification numbers.
If you have not received your identification number by the tax filing deadline, write "Applied For" in the space provided for the EIN.
When Is a New Federal Tax ID Number Needed?
If your business ownership or structure changes, you will likely need to apply for a new taxpayer identification number, depending on your business type. You will not need to apply for a new number if you change only the name or location of your business. Some common reasons for needing a new tax ID number include:
You change your business type; for example, from a sole proprietorship to a partnership or a corporation.
The business is sold to or inherited by a new owner.
You are a sole proprietor and are subject to a bankruptcy proceeding.
These are only a few reasons you might need a new number. For a more detailed list, broken down by business type, see Do You Need a New EIN?
What If I Lose my Taxpayer ID Number?
Should you misplace your taxpayer ID number, the IRS recommends the following actions to retrieve it.
Find the original notice sent by the IRS that assigned you the number. This should have been filed in a safe place as soon as it was received.
If you used the number to open a bank account or apply for a business license, you can contact the bank or licensing agency and get the number from them.
You can call the Business & Specialty Tax Line at 800-829-4933 and ask the IRS to search for your number. As long as you are authorized to receive it, the IRS will give you the number over the phone after confirming your identity.