If you’ve lost track of your LLC’s Employer Identification Number, you can usually find it in minutes by pulling up the IRS confirmation letter (Notice CP 575), any federal tax return the LLC has filed, or the paperwork your bank kept when you opened the business account. When none of those turn it up, the IRS will confirm the number by phone at 800-829-4933 or through your online Business Tax Account. Here is how to find your LLC EIN number using each of these sources, in the order most people get results fastest.
Start With the IRS Confirmation Letter
When the IRS assigns an EIN, it mails a one-page notice called the CP 575 to the address on the application. That letter is the cleanest record you’ll ever have: it shows the nine-digit number, the LLC’s legal name, the filing address, and the federal returns the business is expected to file. If you applied online, the same information appeared on screen at the end of the session, so check your downloads folder and any saved PDFs before assuming the letter is your only copy.
Lost the CP 575? The IRS will issue a replacement called Letter 147C, which carries the same weight for banks and licensing agencies that ask for proof of your number. You request it by phone, covered further down.1Internal Revenue Service. Employer Identification Number
Pull a Prior Federal Tax Return
Every federal return the LLC has filed shows the EIN near the top of page one. Which return depends on how the LLC is taxed:
- Multi-member LLCs taxed as partnerships file Form 1065 and enter the EIN in Item D on page one.2Internal Revenue Service. 2025 Instructions for Form 1065
- LLCs that have elected S corporation treatment file Form 1120-S, also with the EIN in Item D.3Internal Revenue Service. Instructions for Form 1120-S (2025)
- Single-member LLCs without a corporate election are disregarded entities, and their income flows onto the owner’s Schedule C. If the LLC has employees or files excise tax returns, it still has its own EIN, which will appear on those employment or excise filings under the LLC’s name.
An older return works just as well as the most recent one. An EIN doesn’t change once assigned, so a copy from your files, your accountant, or your tax software will do.
Check Payroll Records
If the LLC has employees, the EIN appears on essentially every payroll form. Form 941, the quarterly employment tax return, prints the employer’s EIN at the top of every page.4Internal Revenue Service. Instructions for Form 941 The annual Form 940 for federal unemployment tax and the W-2s issued to employees carry the number as well. Payroll service dashboards typically display it on the account profile.
Check Bank and Loan Paperwork
Banks require an EIN to open a business account for any LLC that isn’t a single-member sole proprietorship, so the account-opening file at your bank will contain it.5U.S. Small Business Administration. Open a Business Bank Account Log in to your business banking portal, or call the bank and ask for a copy of the documents you signed at account opening.
Loans are another reliable source. Lenders record the borrower’s federal tax identification number on promissory notes and security agreements as part of standard verification, so any closing package for financed equipment, real estate, or a line of credit should list it.
Check State and Local Licenses
State and local agencies frequently ask for an EIN on applications for operating licenses, professional permits, and sales tax registrations. The number is often printed on the issued license itself, and at minimum on the application you submitted. Many licensing agencies keep those documents accessible through an online portal, so you may not even need to dig through paper files.
Sign In to the IRS Business Tax Account
The IRS offers a free online portal called the Business Tax Account where an authorized person can view the entity’s basic business profile, including the EIN. You’ll need to sign in with an ID.me or Login.gov credential, verify your identity through the IRS’s authentication provider, and confirm your relationship to the business.6Internal Revenue Service. Business Tax Account The portal is available around the clock, which makes it the fastest option if you have never called the IRS before and would rather avoid a phone queue.
Call the IRS Business and Specialty Tax Line
When nothing else works, call the IRS. The Business and Specialty Tax Line is 800-829-4933, open Monday through Friday from 7:00 a.m. to 7:00 p.m. local time (Alaska and Hawaii follow Pacific time).7Internal Revenue Service. Telephone Assistance Contacts for Business Customers Choose the menu option for Employer Identification Numbers.
Who the IRS Will Talk To
Only an authorized person can receive EIN information by phone. The IRS treats the “responsible party” — the person who owns, controls, or manages the entity’s funds — as the primary authorized individual, typically whoever was listed on the original Form SS-4.8Internal Revenue Service. Responsible Parties and Nominees The agent will ask for your full legal name, your Social Security Number or ITIN, and the LLC’s exact legal name and address as registered.9Internal Revenue Service. Instructions for Form SS-4 (Rev. December 2025)
What You’ll Get on the Call
Once your identity is verified, the agent will read the EIN back to you on the line. Ask for Letter 147C at the same time if you need written confirmation for a bank or agency; the IRS will mail it to the address on file.1Internal Revenue Service. Employer Identification Number Hold times run long during the day, so early morning or later in the week tends to go faster.
Let a Tax Professional Retrieve It
If you’d rather not make the call yourself, you can authorize an attorney, CPA, or enrolled agent to do it. There are two IRS forms for that:
- Form 8821 (Tax Information Authorization) lets a named designee review or receive your confidential tax information, including the EIN. It doesn’t allow the designee to represent you or make decisions on your behalf, and any individual, firm, or organization can be named.10Internal Revenue Service. Power of Attorney and Other Authorizations
- Form 2848 (Power of Attorney and Declaration of Representative) goes further, authorizing the representative to act on your behalf before the IRS. For EIN work, list “EIN Application” in the Description of Matter column on Line 3, enter “Form SS-4” as the tax form, and write “Not Applicable” for the year; because this type of authorization isn’t recorded on the IRS’s central file, the representative submits the form directly to the office handling the matter.11Internal Revenue Service. Instructions for Form 2848 (Rev. September 2021)
Form 8821 is usually enough if all you need is someone to retrieve the number. Reach for Form 2848 when you also want that person handling broader tax matters going forward.
Update Your Address First If the LLC Has Moved
Anything the IRS mails you — the replacement CP 575, Letter 147C, transcripts — goes to the address on file. If your LLC has relocated since the EIN was issued and you never updated the IRS, the paperwork will land at the old address and you may never see it.
File Form 8822-B (Change of Address or Responsible Party — Business) before requesting mailed documents. The same form is required whenever the responsible party changes, and the update must be reported within 60 days.12Internal Revenue Service. Form 8822-B Change of Address or Responsible Party – Business Mail it to the processing center that matches the LLC’s old business address: Kansas City, MO 64999 for businesses in the eastern half of the country, and Ogden, UT 84201-0023 for those in the western half and outside the U.S. Allow four to six weeks for the change to take effect.13Internal Revenue Service. Address Changes
Don’t Let a Missing EIN Push You Past a Filing Deadline
A misplaced EIN is not a valid reason to skip a filing deadline, and the IRS charges steep late-filing penalties on partnership and S corporation returns. The failure-to-file penalty runs $255 per partner or shareholder per month (or partial month), for up to 12 months, on returns due after December 31, 2025.14Internal Revenue Service. Failure to File Penalty A four-member LLC that files three months late owes $3,060.
If a deadline is close and you still can’t find the number, the IRS lets you write “Applied for” and the date you requested the number in the EIN field of the return.2Internal Revenue Service. 2025 Instructions for Form 1065 File on time with that placeholder. The consequence of a missing EIN on a timely return is much smaller than the consequence of no return at all.