How to Find My EIN Number Online: Quick Guide

How to Find Your EIN Number, and Why It Matters for Your Business

Most business owners go looking for their Employer Identification Number (EIN) at an inconvenient moment: partway through a bank application, a payroll setup, or a vendor onboarding form, with a nine-digit blank to fill.

An EIN is rarely lost, only misplaced. It sits on a short list of documents you probably already have, and if none turn up, the IRS will confirm it over the phone. Looking up another company's EIN is a different problem with different answers. This guide covers both, plus how to apply.

If you're searching for phrases like "how to find my EIN number" or "EIN number online," this quick guide explains what an EIN number is, where to locate yours, and how to run an EIN lookup when you need another company's ID.

What is an Employee Identification Number (EIN) and Why Do You Need One?

An EIN is a nine-digit number the IRS assigns to identify a business entity for federal tax purposes. Written as XX-XXXXXXX, it also goes by federal tax ID, federal tax identification number, tax ID number, and business tax ID. It works like a Social Security number – it’s a permanent identifier that government agencies and financial industries use to look up your business.

Most businesses that hire, file a business tax return, or open bank accounts under the business name need an EIN. Sole proprietors with no employees are the common exception; they can often file under their SSN. Here's where an EIN comes up:

Filing business tax returns. The IRS requires an EIN on business returns.
Running payroll and withholding taxes, including W-2 and 1099 forms.
Opening a business bank account, which most banks and credit unions require an EIN to do.
Applying for a business loan or credit card. Lenders tie business credit reports to your EIN, and some issuers approve on an EIN alone.
Applying for business licenses and permits, and for tax exempt status if you're a nonprofit.
Protecting your SSN, since a sole proprietor using an EIN on a W-9 doesn't hand a Social Security number to every client.

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Difference Between EIN and TIN

EIN may often get confused with TIN, or Taxpayer Identification Number. Both EIN and TIN refer to identification methods for tax purposes, with TIN being the more general term for any identification that the IRS uses to track taxpayers. EIN is a specific type of Taxpayer Identification Number tailored to businesses. Here's the breakdown:

TIN (Taxpayer Identification Number): any number the IRS uses to identify taxpayers. This may include EIN for businesses, SSN (Social Security Number) for individuals, or ITIN (Individual Taxpayer Identification Number) for individuals without an SSN
EIN (Employer Identification Number): a tax ID number or type of TIN specifically for business entities

This distinction can become particularly valuable to note if you're a sole proprietor. For sole proprietors, you may file taxes under your SSN; however, if you register your business as an LLC or corporation, that means you must apply through an EIN application to receive a new EIN with the IRS. Failure to apply correctly for an EIN for your LLC can result in tax filing penalties.

How to Find Your EIN Number

If you've already applied for and been issued an EIN, there are several ways to locate it. Fortunately, EINs are more commonly shared and made publicly available, so there are a number of options and business documents available where you can locate your tax ID number.

Here are some recommended documents to check:

EIN confirmation letter: when your EIN is confirmed, the IRS will send you a CP 575 Form, your EIN confirmation letter, which includes your EIN. This form may be digital depending on how you applied
Tax returns: you'll need your EIN to file taxes, so it will appear on any documents for your business tax return. Typically, your EIN should be listed at the top of these documents
Payroll forms: on payroll forms, such as the W-2 or 1099, your EIN is required and must therefore be listed
Bank account statements: if you've opened a business bank account, your EIN is very likely required. It will be recorded on documents and often found on your banking site
Loan or license applications:business loan files, credit applications, and permit paperwork all require EINs. Other licenses and loans may also be listed - check any recent documents for an EIN listing

If you can't locate your EIN on a business document, you can contact the IRS directly. If you take this approach, be prepared to provide your legal name, business address, and details about your business ownership. Many business owners who search "how to find my EIN number" find that checking these documents first saves time before calling the IRS.

Listed under Business Information, you'll find your EIN alongside your legal entity name and NAICS code.

How to Find an EIN Number for a Business (if it's not yours)

It may be the case that you need to locate another company's Employer Identification Number when:

Filing 1099-NEC forms to report contractor payments over $600
Completing W-9 forms when working with vendors or freelancers
Verifying business legitimacy before entering into business dealings or large financial transactions
(If you're an individual) Filing unemployment benefits, where your employer's EIN may be required
Regulatory compliance in industries like insurance, lending, or healthcare

There may be several reasons why you need a company's EIN, but locating it can sometimes be challenging.

How to find EIN details for another business using reliable sources

While EINs are more commonly available than SSNs, the IRS does not allow a simple EIN search for all companies.

Fortunately, there are still many ways to locate another company's EIN:

Ask the company directly: companies may often share EIN information via documents like W-9. Depending on your B2B relationship, you may be able to contact the company directly
SEC filings: public companies list EINs in documents filed with the SEC, including 10-K or 20-F
IRS nonprofit database: the IRS's Tax Exempt Organization Search can help you find EINs for nonprofit organizations
Business credit reports: some available reports from credit bureaus may include EINs
Third-party EIN search platforms: services like Middesk provide an EIN lookup, although these sites are not verified

Still stuck? Reach out to the company directly; emails and notifications can get overlooked, and the most reliable way to confirm an organization's EIN is directly from the company itself.

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Can I Change or Remove an EIN?

Once assigned, your EIN is permanent. You cannot delete it, but you can close the IRS account tied to it if your business is no longer active.

If you want to stop using your EIN

Send a closure request (often a letter) to the IRS
Include your legal name, EIN, business address, and reason for closure
Attach your final tax return marked as a final filing

If you're hoping to change your business without changing or recreating an EIN, you'll need to contend with some limitations. For instance, some business changes will require that you create a new EIN.

Here's a breakdown:

You'll need to apply for a new EIN if:

You change your business structure (e.g., sole proprietorship to corporation)
Significant ownership changes
You start a new corporation or partnership

You can keep your EIN if:

You change your business name
You change your business address

Even when making minor changes that won't impact your EIN, you must still notify the IRS. If you have more than one business, using Slash's multi-entity tools can help you manage multiple EINs for each entity.

How to Get an EIN Number Online, By Mail, or By Phone

Applying for an EIN is free; the IRS charges nothing and warns businesses about sites that charge for the service. There are three different routes you can take to apply, depending on where you and your business are based.

Apply online through the IRS application portal

The fastest option, and the one the IRS prefers. Apply on the IRS website and it validates during the session and issues the EIN immediately. The responsible party (whoever controls the entity and its funds) needs a valid SSN or ITIN, and the business's principal location must be in the U.S. or a U.S. territory.

The tool runs on a schedule, not around the clock: Monday through Friday, 6 a.m. to 1 a.m. Eastern; Saturday, 6 a.m. to 9 p.m.; Sunday, 6 p.m. to midnight. One EIN per responsible party per day. Additionally, the IRS online application has to be finished in one session and times out after 15 minutes of inactivity, with no option to save or return to your progress.

Submit Form SS-4 via fax or mail

Send Form SS-4 to the service center for your state. With a return fax number, the IRS typically faxes the EIN back within four business days. By mail, plan on about four weeks.

Call the IRS if you're an international applicant and don't have an SSN or ITIN

If your principal place of business is outside the U.S. you can't use the online tool, but you can apply by phone at 267-941-1099, Monday through Friday, 6 a.m. to 11 p.m. Eastern. The line isn't toll-free. The caller must be authorized to receive the EIN and able to answer the Form SS-4 questions, so fill the form out before dialing. A foreign responsible party without an SSN or ITIN can write "Foreign" in that field.

What to do once you have your EIN

If you’re rummaging through old paperwork to locate your EIN, there’s a good chance you’re preparing to apply for a new business bank account. If that’s your situation, consider Slash.¹

A business bank account usually stops at checking and a debit card. Everything past that gets bought separately: a corporate card program from one vendor, bill pay from another, a treasury product from a third, and a credit line from whoever will underwrite you. Each one is its own login, its own approval chain, and its own thing to reconcile at month end.

Slash is built the other way around, with cards, payment rails, payables, treasury⁶, and financing⁵ all part of the same product, instead of things you bolt on as the company gets more complicated. Here’s what you get with a Slash account:

Slash Visa Platinum Card: Corporate charge cards that can earn up to 2% cash back with granular spend controls, spend limits, and card grouping.
Business banking: FDIC-insured business checking, protected up to $150M through Column N.A.'s insured cash sweep network.²
Multiple payment methods: Send and receive funds via same-day ACH, wires on SWIFT to 180+ countries, RTP, FedNow, and stablecoin transfers in USDC or USDT.⁴
Accounts payable and receivable: Create invoices, track payment status, and collect payments via multiple methods all in your dashboard. For your bills, Slash can parse an uploaded invoice, route each bill for approval, and track its status from pending to paid, so payables don't slip through the cracks.
Integrated treasury: High-yield treasury accounts earning up to 3.86% annualized yield backed by Morgan Stanley and BlackRock money market funds, with no minimum balance to get started.
Flexible financing: Access to a line of credit in your Slash dashboard to support cash flow gaps or temporary funding, with 30, 60, or 90 days repayment terms.

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Frequently asked questions

Do sole proprietors need an EIN?

Not always. A sole proprietor can use their Social Security Number, but an EIN is often required for opening a business bank account or applying for a business loan. You'll need to create an EIN if you transition to a corporation or register for an LLC.

Do you need a different EIN if you have multiple LLCs?

Yes. Each business entity needs its own EIN. Slash offers multi-entity management support, helping business owners streamline the management of multiple businesses in one dashboard.