How to Find a Business Tax ID Number (EIN): IRS Lookup Steps

To find a business tax ID number (EIN) that belongs to you, start with the paperwork you already have: the IRS’s original CP 575 confirmation notice, a prior federal tax return, a business bank statement, or a state license. If none of those turn it up, sign in to the IRS Business Tax Account online or call the IRS Business and Specialty Tax Line at 800-829-4933 to have an agent verify your identity and read the number back. To find another company’s EIN, ask the business for a Form W-9, or look it up in a public database such as SEC EDGAR for public companies or the IRS Tax Exempt Organization Search for nonprofits.

Look Through Your Own Records First

The fastest place to find your EIN is a document you already own. When the IRS first issued the number, it mailed a CP 575 confirmation notice to the address on the application. If you applied online, you may have saved a PDF at the end of the session. Search your email and cloud storage for “CP 575” or “EIN assignment.” The IRS does not send EIN confirmations by email, so any digital copy is one you saved yourself.

If the CP 575 is gone, prior federal tax returns are the next best source. Your EIN appears near the top of Form 1120 for corporations, Form 1065 for partnerships, Schedule C of Form 1040 for sole proprietors who obtained one, and Form 990 for tax-exempt organizations.¹ Payroll filings such as Form 941 and Form 940 also print the EIN on every page.

A few other everyday documents almost always carry the number:

The account agreement or a monthly statement from your business bank.
Business licenses and permits from state or municipal agencies.
Loan agreements and insurance policy declarations.
Any prior IRS notice sent to the business, which prints the EIN at the top.

Retrieve It Online Through the IRS

The IRS Business Tax Account portal lets eligible owners view their business profile and download an entity transcript that shows the EIN.² Access requires identity verification through ID.me with a government-issued photo ID. Not every entity type is supported yet, but when it works, it is the fastest route and needs no phone call.

If you cannot use the portal, you can still order a business tax transcript online, by phone, or by mailing Form 4506-T. The transcript lists your EIN along with other data on file.³

Call the IRS Business and Specialty Tax Line

When records and the online portal are out of reach, call 800-829-4933. The line runs Monday through Friday, 7 a.m. to 7 p.m. local time; callers in Alaska and Hawaii follow Pacific time.⁴ International callers use 267-941-1099, Monday through Friday, 6 a.m. to 11 p.m. Eastern time.⁵

Before you dial, have the following ready so the agent can verify you:

The entity’s legal name exactly as filed on the original application.
The business address the IRS has on file, which may not be your current one.
The responsible party’s name and Social Security Number.⁶
The approximate date the entity was formed.

If verification clears, the agent reads the EIN over the phone. You can also ask for a 147C verification letter, which is mailed to the address on file and serves as an official replacement for the CP 575.⁵ Average waits run about 15 minutes outside of filing season and longer between January and April.⁷

Let Someone Else Make the Call

If you cannot call yourself, you can authorize an accountant or attorney to do it. Two forms cover the two situations:

Form 2848, Power of Attorney, lets an attorney, CPA, or enrolled agent represent you before the IRS and request the EIN. The representative must be eligible to practice before the IRS.⁸
Form 8821, Tax Information Authorization, lets someone inspect and receive your tax information, including the EIN, without acting as a representative.⁹

The form must be on file with the IRS before the call. If you only need the number confirmed, Form 8821 is the simpler option.

When There Is No EIN To Find

Not every business has one. A sole proprietor with no employees and no excise tax filings may have been using a Social Security Number as the taxpayer identification number all along, in which case there is nothing to retrieve.⁵ Sole proprietors do need an EIN once they hire employees, operate a Keogh or solo 401(k), file excise tax returns, or buy an existing business. If one of those applied to you and the number was later lost, the same retrieval methods work; the EIN will appear on Schedule C of Form 1040 rather than a separate business return.

Make Sure You Still Qualify To Use the Old Number

Before chasing down an old EIN, confirm it is still the right one. The IRS requires a new EIN when the ownership or structure of the entity changes, not just its name or address.¹⁰ Common triggers for a new number:

A sole proprietor incorporates, forms a partnership, or files for bankruptcy.
A corporation receives a new charter from the secretary of state, merges into a new corporation, or converts to a partnership or sole proprietorship.
A partnership incorporates, dissolves and reforms, or becomes a sole proprietorship as one partner takes over.
An LLC terminates and a new entity forms, or a single-member LLC has to begin filing employment or excise taxes.
A revocable trust becomes irrevocable, or a living trust becomes testamentary.

You keep the existing EIN when you rename the business, change addresses, or are the surviving corporation in a merger.¹⁰ Using the wrong number on a filing can cause mismatches, delayed refunds, and IRS notices.

Finding Another Business’s EIN

Several legitimate paths lead to another company’s EIN, depending on what kind of entity it is.

Ask for a Form W-9

The simplest option is to request a completed Form W-9 from the business. A W-9 collects the taxpayer identification number and certifies it under penalties of perjury. Companies expect to provide them, because anyone paying them for services needs the number to file information returns.¹¹

Public Companies on SEC EDGAR

For any company traded on a public stock exchange, the SEC’s EDGAR database is free to search.¹² Pull up a Form 10-K annual report or Form 8-K current report and the EIN is printed on the cover page. EDGAR also offers a full-text search across filings.¹³

Nonprofits Through IRS Tax Exempt Organization Search

If the entity is a nonprofit, the IRS Tax Exempt Organization Search returns the EIN along with the determination letter and Form 990 filings.¹⁴ Use quotation marks around the full name and skip common words like “the” or “foundation” to narrow the results.

State Business Records

Secretary of state websites in many states let you search business registrations. Some display the EIN, others redact it. Even without the number, these records confirm the legal name and registered agent, which helps direct a W-9 request to the right person.

Keeping the Number Safe Going Forward

Once the EIN is back in hand, store the 147C letter or entity transcript in two places, one digital and one physical. If the business changes its address or its responsible party, file Form 8822-B with the IRS within 60 days of the change.¹⁵ Skipping that update can send IRS notices, including deficiency notices, to someone who no longer runs the business while penalties and interest keep accruing. The responsible party on file must be an individual who owns or controls the entity, not another company.¹⁶ Keeping that record current also means whoever inherits the role can call the IRS and retrieve the EIN when the time comes.

1
Internal Revenue Service. Instructions for Form 1120 (2025)
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Internal Revenue Service. Business Tax Account
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Internal Revenue Service. Get a Business Tax Transcript
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Internal Revenue Service. Telephone Assistance Contacts for Business Customers
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Internal Revenue Service. Employer Identification Number
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Internal Revenue Service. Responsible Parties and Nominees
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Internal Revenue Service. Let Us Help You
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Internal Revenue Service. Instructions for Form 2848 (Rev. September 2021)
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Internal Revenue Service. Instructions for Form 8821
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Internal Revenue Service. When to Get a New EIN
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Internal Revenue Service. Instructions for the Requester of Form W-9
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U.S. Securities and Exchange Commission. Search Filings
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Securities and Exchange Commission. EDGAR Full Text Search
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Internal Revenue Service. Search for Tax Exempt Organizations
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Internal Revenue Service. Form 8822-B, Change of Address or Responsible Party – Business
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Internal Revenue Service. Instructions for Form SS-4 (12/2025)