It happens to the best of us. You’re sitting there, staring at a bank application or a vendor contract that’s asking for those nine digits, and your mind goes totally blank. You know you have one. You remember the day the IRS confirmation letter arrived in the mail, but now? That piece of paper is probably living in a "safe place" that’s currently invisible to the human eye. If you’re frantically searching for how to look up my EIN, take a breath. You don't need to re-apply, and you definitely don't need to pay some random website $300 to "recover" it for you.
Losing an Employer Identification Number is a rite of passage for small business owners. Honestly, it’s basically the corporate version of losing your car keys. The good news is that because this number is tied to almost everything your business does, it leaves a massive paper trail. You just have to know which breadcrumbs to follow.
Start With the Paper Trail You Already Built
Before you even think about calling the IRS—which, let’s be real, is a test of patience most of us aren't ready for on a Tuesday morning—look at your own digital and physical files. The most obvious place is that original CP 575 notice. That’s the official "Welcome to the IRS" letter you got when the number was first assigned. If you applied online, you might have a CP 575A version.
Check your email. Search for terms like "EIN," "Tax ID," or "IRS Confirmation." You’d be surprised how many people find it as a PDF attachment in an email sent to their accountant three years ago. If you use a cloud storage service like Google Drive or Dropbox, check there too. Sometimes we’re smarter than we remember and actually scanned the document.
But maybe the digital search came up empty. Fine. Think about your bank. Did you open a business checking account? You literally cannot do that without an EIN. Log into your online banking portal and look at your account profile or the original "Know Your Customer" (KYC) documents you signed. If it's not visible in the app, a quick message to your business banker usually solves the mystery in minutes. They have it on file. They need it to keep your account open. They’ll give it to you once you prove you are who you say you are.
Licenses, Permits, and the Paperwork Nightmare
Your EIN is like your business’s Social Security number. It’s everywhere. If you have a local business license or a permit from your city or county, check those applications. Most local governments require your federal tax ID to issue a license.
Did you apply for an S-Corp election? Look for Form 2553.
Did you file taxes last year? Look at your Form 1120 (for corporations) or 1065 (for partnerships).
The number is right there at the top.
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If you’re a freelancer or a single-member LLC and you’ve done work for a bigger company, you probably sent them a W-9. Search your "Sent" folder for "W-9" or "Form W-9." You’ve already typed those nine digits into that little box at least once. It’s waiting for you in your outbox.
The Professional Safety Net
If you have an accountant or a bookkeeper, they are your best friend right now. They probably have your EIN saved in their professional tax software, taped to a physical folder, and burned into their retinas. A thirty-second phone call to your CPA is significantly faster than any other method on this list. Even if you only used a tax prep service once a couple of years ago, they are legally required to keep records of your filings for a certain period. Reach out.
When All Else Fails: Calling the IRS
Okay, let’s say you’ve searched every drawer, checked every email, and your bank is being difficult. You have to go to the source. The IRS has a specific department for this: the Business & Specialty Tax Line.
You can reach them at 800-829-4933.
They are open from 7:00 a.m. to 7:00 p.m. local time, Monday through Friday.
Here is the thing: do not call at 10:00 a.m. on a Monday. You will be on hold until the next solar eclipse. Try calling right when they open at 7:00 a.m. sharp.
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When you get a human on the line, tell them you need an EIN search. They aren't going to just blurt it out, though. You have to be an "authorized person." Generally, that means you're the sole proprietor, a partner in the partnership, a corporate officer, or a trustee. They are going to grill you. Be ready with:
- Your full legal name.
- Your Social Security Number.
- The legal name of the business (exactly as it was registered).
- The business address you used when you applied.
If you’ve moved since you got the EIN and didn't update your address with the IRS, this part gets tricky. Use the old address. They need to match what’s in their database, not where you currently receive mail.
Public Records and the "Hidden" Lookup
If you are trying to find the EIN for a company that isn't yours—maybe you’re a vendor trying to verify a client or you’re doing due diligence—the process is different. You can't just call the IRS and ask for someone else's tax ID. That’s a privacy violation.
However, if the company is publicly traded, you’re in luck. The SEC requires public companies to disclose their EIN on their filings. Go to the SEC EDGAR database and search for the company’s 10-K (annual report). The EIN is usually listed right on the first page. It’s public knowledge for them.
For non-profits, use Candid (formerly GuideStar) or the IRS Tax Exempt Organization Search tool. Non-profits have to be transparent with their filings (Form 990), and those forms always include the EIN.
For a private company that isn't yours? You mostly have to ask them. Or, if you’ve paid them more than $600 in a year, you should already have their W-9 on file. If you don't, you need to request it for your own tax compliance.
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Misconceptions About EIN Lookups
A lot of people think there is a "National EIN Directory" where you can just type in a business name and get a number. There isn't. The IRS doesn't want that information floating around freely because an EIN can be used for identity theft and fraudulent tax filings.
Another common mistake: searching the Secretary of State website. While your state’s SOS will show you your State Entity ID or Charter Number, they rarely show the Federal EIN. Those are two different numbers. Don't confuse them, or you'll have a very confusing conversation with your bank later.
Also, be wary of third-party websites that claim they can look up your EIN for a fee. Most of these sites are just using public data you could find yourself, or they are just trying to harvest your business information. If a site looks like it was designed in 2004 and asks for your SSN to "search" for your EIN, run away. Fast.
Avoiding This Mess Next Time
Once you find those nine digits—and you will—do yourself a huge favor.
- Digitize it: Take a photo of the CP 575 notice and put it in a "Tax Info" folder on a secure cloud drive.
- Physical backup: Print two copies. Put one in your primary business folder and one in a fireproof safe.
- Password Manager: Add a secure note in your password manager (like 1Password or Bitwarden) labeled "Business Tax ID."
It seems like overkill until you’re in the middle of a closing or a loan application and you need that number "five minutes ago."
Your Actionable Checklist
If you are currently without your number, follow these steps in this exact order:
- Check your email for "CP 575," "EIN," or "W-9."
- Open your last filed tax return. The number is on the first page of the federal return.
- Log into your business bank account and download your original account opening documents.
- Call your accountant. They likely have it saved in their client portal.
- Contact the IRS at 800-829-4933 as a last resort, calling early in the morning to minimize hold times.
Once you have the number, immediately update your records so you never have to go through this scavenger hunt again. Having your EIN ready is a small but vital part of keeping your business's administrative engine running smoothly.