To find your FEIN number, start with the IRS confirmation letter you received when the number was first assigned, then check your most recent federal tax return; if neither is available, your bank records, IRS online account, or a call to the IRS Business and Specialty Tax Line will get you the nine-digit number in the format XX-XXXXXXX. Which route works depends on what paperwork you still have.
Start With the IRS Assignment Letter
The fastest source is the CP 575 notice, the official letter the IRS sends when it first issues an EIN. It shows the number itself, your business’s legal name, filing address, the tax forms your business is expected to file, and the due dates. The IRS sends this letter once and does not reissue it, so if you saved it the search ends there.
If you applied by phone using Form SS-4, the IRS instructions tell applicants to write the assigned number on the form and keep it. If you applied online, the confirmation was available to download at the end of the session.1Internal Revenue Service. Instructions for Form SS-4 (12/2025) Either copy sits with your formation paperwork in most businesses.
Pull a Previously Filed Tax Return
Every federal business return prints the EIN near the top of the first page. Where exactly depends on how the business files:
- Corporations: Form 1120 has an “Employer Identification Number (EIN)” field in the header.2Internal Revenue Service. Instructions for Form 1120 (2025) – General Instructions
- Partnerships: Form 1065 shows the EIN in the identification area at the top of the return.3Internal Revenue Service. Instructions for Form 1065 (2025) – Who Must File
- Sole proprietors: Schedule C, filed with Form 1040, has an “Employer ID number (EIN)” field on line D of the identification section.4Internal Revenue Service. 2025 Schedule C (Form 1040)
Employer payroll returns work the same way. Quarterly Form 941 filings, kept by whoever runs your payroll, require the EIN to report federal withholdings. If a tax preparer handled the filings, they should have digital copies and can send the number back to you within a day.
Check Bank and Business Records
Banks collect the EIN when a business account is opened, so the original application, the account agreement, monthly statements, and business credit agreements all print the number alongside the account holder’s name. Financial institutions retain this information to report interest income and meet federal record-keeping rules.5eCFR. 31 CFR Part 1022 – Rules for Money Services Businesses
A few other business documents commonly carry the EIN:
- State and local business license and permit applications, which often require the EIN as part of registration.6U.S. Small Business Administration. Get Federal and State Tax ID Numbers
- Commercial insurance policies and business loan paperwork.
- Payroll service records, if you have employees.
Checking your own files first keeps the number off the phone and out of any external system. It is usually faster too.
Use Your IRS Online Account
If the paperwork route fails, the IRS has two online options.
Business Tax Account
The Business Tax Account portal at IRS.gov lets an authorized user sign in and view the business profile the IRS has on file. Sole proprietorships, partnerships, S corporations, and C corporations can all use it to see identifying information tied to the business.7Internal Revenue Service. Business Tax Account
Entity Transcript
An IRS entity transcript verifies what is in IRS records for the business, including the EIN, filing requirements, and classification. You can view, print, or download it inside the Business Tax Account, or request it by mail with Form 4506-T. The online version is available immediately; the mailed request takes longer.8Internal Revenue Service. Get a Business Tax Transcript
Call the IRS for Letter 147C
When nothing turns up, call the IRS Business and Specialty Tax Line at 800-829-4933. The line is open Monday through Friday, 7:00 a.m. to 7:00 p.m. local time, with Alaska and Hawaii on Pacific time.9Internal Revenue Service. Telephone Assistance Contacts for Business Customers Only an authorized person can make the request: a sole proprietor, a corporate officer, or a partner. Have your Social Security number and the business’s legal name and address ready for identity verification.
After verifying you, the agent will read the EIN over the phone. You can also ask for Letter 147C, a written confirmation of the previously assigned EIN.10Internal Revenue Service. Employer Identification Number That letter takes the place of the original CP 575 when a bank, lender, or licensing agency wants official documentation. Write down the agent’s name and the date of the call in case the letter is slow to arrive.
Finding Someone Else’s EIN
If the number you need belongs to another business, such as a vendor you are verifying or a charity you plan to donate to, two kinds of public filings usually have it.
For publicly traded companies, the cover page of SEC Form 10-K shows the IRS Employer Identification Number next to the company name and state of incorporation.11U.S. Securities and Exchange Commission. Form 10-K The SEC’s EDGAR database is searchable by company name.
For nonprofits, tax-exempt organizations must make their Form 990 returns, which include the EIN, available for public inspection.12Internal Revenue Service. Exempt Organization Public Disclosure and Availability Requirements Those returns stay publicly available for three years from the filing due date or the actual filing date, whichever is later.13Internal Revenue Service. Public Disclosure and Availability of Exempt Organization Returns and Applications – Public Disclosure Overview Third-party databases such as Candid, formerly GuideStar, aggregate Form 990 filings so you can search by organization name.
One boundary worth noting: the IRS will not give the EIN of a business you are not authorized to represent. For anyone else’s number, the public filings above are the route.