You're digging through a junk drawer or a digital folder titled "Important Stuff 2022," and it’s just not there. That nine-digit number, the Employer Identification Number (EIN), is basically the Social Security number for your company, and yet it vanishes the moment you actually need it for a bank loan or a vendor contract. If you need to look up federal tax id for business details right now, don't panic. Honestly, it happens to the best of us. Most business owners treat that IRS confirmation letter like a golden ticket until they realize they haven't seen it in three years.
Finding it isn't always a straight line. Depending on whether you're looking for your own number or someone else's, the path changes significantly. Let's get into the weeds of how this actually works in the real world.
Where Your EIN Is Probably Hiding Right Now
Most people think they need to call the IRS immediately. Don't do that yet. You'll be on hold for forty minutes listening to elevator music only to realize the number was in your inbox the whole time.
Check your email for "CP 575." That’s the official notice the IRS sent when you first formed the entity. If you applied online, you likely got a PDF download right then and there. Search your digital archives for terms like "EIN Confirmation" or "Department of Treasury."
If the digital trail is cold, look at your last bank statement. Seriously. Most business bank accounts require the EIN to open, and while they don't always print the full number on every page for security, it’s usually on the original account opening documents. If you have a dedicated banker, a quick phone call—after they verify your identity, of course—can usually solve the mystery in two minutes.
Then there are the permits. Did you apply for a local liquor license? A sales tax permit? A professional license through the state? All of these applications require that federal tax ID. Your local city clerk’s office or the state Department of Revenue already has this on file.
The Paperwork Trail You Forgot About
If you've ever hired an independent contractor and sent them a 1099, or if you’ve filed a tax return (Form 1120 for corporations or 1065 for partnerships), the number is right there at the top. It’s bold. It’s hard to miss once you’re looking for it.
Even your old payroll records will have it. If you use a service like Gusto or ADP, just log in and look at your company profile. They can't move money without that ID. It's the anchor for every financial transaction your business has ever made.
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How to Look Up Federal Tax ID for Business Info on Other Companies
Now, what if you aren't looking for your own number? Maybe you're a contractor trying to verify a client, or you're doing due diligence on a potential partner. This is where it gets a bit more "detective-ish."
Publicly traded companies are easy. They are an open book because the SEC demands it. You go to the SEC's EDGAR database. Search the company name. Look for their most recent Form 10-K (annual report). The EIN is usually listed right on the first page, near the company address. It's public record. No hurdles.
Private companies? That’s a different beast entirely.
The IRS does not have a public "Yellow Pages" for EINs. They protect that data to prevent identity theft. However, you can often find what you need through state-level filings. Most Secretary of State websites have a business search tool. While they primarily show the state-issued charter number, sometimes the federal EIN is included in public filings or initial registration documents, though this is becoming rarer as privacy laws tighten.
Industry-Specific Shortcuts
Some industries have a "tell." If you're looking for a non-profit, use the IRS Tax Exempt Organization Search tool or Guidestar. Non-profits have to be transparent. Their Form 990 is public, and the EIN is always right there at the top of the first page.
For construction or transportation companies, check federal or state licensing boards. Sometimes, those public databases include tax identifiers to prove the business is a legitimate, registered entity.
When You Have to Call the IRS (The Last Resort)
If you've exhausted the "look up federal tax id for business" DIY methods, you have to talk to a human at the IRS. It’s not as scary as it sounds, but it is slow.
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You call the Business & Specialty Tax Line at 1-800-829-4933. They are open from 7:00 a.m. to 7:00 p.m. local time, Monday through Friday.
Here is the catch: they won't just give the number to anyone. You must be an "authorized person." That means you are the sole proprietor, a partner in the partnership, a corporate officer, or a trustee. They will grill you. They'll ask for your Social Security number, your birth date, the legal address of the business, and maybe even the date you started. If you stumble on these, they'll hang up. It’s a security measure, and honestly, you want them to be that strict.
The Misconception About "Free" Online Lookups
You’ll see websites promising a "Free EIN Lookup." Be careful. Most of these are just data scrapers that want your email address so they can sell you registered agent services or legal help.
The only truly free, official way to look up federal tax id for business data for a private company is through the methods mentioned above—checking your own records or public SEC/Non-profit filings. If a site asks for a credit card to "verify your identity" for a public record search, run.
Some paid databases like Dun & Bradstreet (D-U-N-S numbers) are legitimate for B2B credit checks, but even they might not give you the raw EIN without a full report purchase.
Why Your EIN Might Be "Missing" Even if You Have the Number
Sometimes you have the number, but it doesn't "work." You try to open a bank account and they say it’s not in the system.
This usually happens with new businesses. It takes time—sometimes up to two weeks—for a newly issued EIN to migrate through all the federal databases. If you just got your number yesterday and are trying to apply for a complex federal grant today, the systems might not be talking to each other yet.
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Also, check for typos. It's a 9-digit number formatted as XX-XXXXXXX. It is not the same as your state tax ID, which often has a different number of digits or includes letters. Mixing these two up is the most common reason people think their federal ID is "wrong."
The "Dormant Business" Problem
If your business was inactive for years and you're trying to revive it, the IRS might have marked the account as "dormant." The number is still yours—EINs never expire and they are never reassigned to another business—but you might need to "re-activate" it by filing a delinquent return or sending a letter to the IRS office where you file your returns.
Actionable Steps to Take Right Now
Stop scrolling and do these three things to solve this permanently.
- Check your 2024 or 2025 tax returns. The EIN is on the first page of your federal return. If your accountant has them, email them right now. They can find it in thirty seconds.
- Search your "Sent" folder. Look for emails you sent to your bank, your insurance agent, or a landlord. You likely had to provide your EIN in an application or an onboarding form.
- Create a "Master Business Profile." Once you find the number, don't just write it on a post-it. Put it in a secure password manager or a locked digital note. Include your EIN, your State ID, and your formation date.
If you're trying to find another company's ID and they aren't public, just ask them. It’s a standard request in business. Ask for their W-9 form. Any legitimate business will have a W-9 ready to go—it’s the formal way companies exchange tax ID information for payment purposes. It saves you the headache of playing private investigator.
For your own peace of mind, if you've lost the physical CP 575 letter, you can request a "147C letter" from the IRS. This is an official "EIN Verification Letter." You get it by calling that 800-number mentioned earlier and asking for a replacement verification. They can often fax it to you on the spot if you still have access to a fax machine (or a digital fax service), which is much faster than waiting for the mail.
Lock that number down. You'll need it again sooner than you think.