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The Daily Insight

What if I lost my SS4?

Author

John Thompson

Published Feb 26, 2026

You can request a replacement copy by calling the IRS Business and Specialty Tax Line. The phone number is (800) 829-4933, and the line is open from 7 a.m. to 7 p.m., taxpayer local time, Monday through Friday. The tax specialist will ask you to provide your EIN and some identifying information about your business.

How do I verify my SS4?

To check on the status of your federal tax ID number, contact the IRS by telephone at 800-829-4933. Press the number on your touchtone keypad as directed by the automated recording to have your call directed to “Employee or Federal Identification Number inquiries.” The wait on hold can be lengthy, so be patient.

What are the instructions for form SS-4?

Instructions for Form SS(Rev. December 2019)-4 Application for Employer Identification Number (EIN) Department of the Treasury Internal Revenue Service Section references are to the Internal Revenue Code unless otherwise noted. General Instructions Use these instructions to complete Form SS-4, Application for Employer Identification Number (EIN).

Where can I get a copy of my SS4 letter?

If you do not wish to apply online through the online application tool on the IRS website you can complete a form and send it off it to the department of treasury. If your lender requires a Form SS-4 copy, you’ll need to provide a copy or obtain proof of having submitted the form to the IRS.

Do you have to sign form SS-4 before contacting IRS?

Note. It will be helpful to complete Form SS-4 before contacting the IRS. An IRS representative will use the information from Form SS-4 to establish your account and assign you an EIN. Write the number you’re given on the upper right corner of the form and sign and date it. Keep this copy for your records.

When to file a sole proprietorship form SS-4?

Generally, a sole proprietor should file only one Form SS-4 and needs only one EIN, regardless of the number of businesses operated as a sole proprietorship or trade names under which a business operates. However, if a sole proprietorship incorporates or enters into a partnership, a new EIN is required.