3 quick ways to find your employer identification number (EIN)

Before you make a single phone call, check these three sources. Most business owners find their EIN quickly this way. If none of them pan out, the sections below cover every other place it's likely to be hiding.

Your IRS confirmation letter (CP 575)

When the IRS assigns an EIN, it sends a confirmation notice called the CP 575. This is the original source of record for your number, and it should be stored with your other foundational business documents alongside your operating agreement and IRS correspondence. If you applied online, the IRS issued the CP 575 as an immediate PDF download at the end of the session. If you applied by mail, it arrived by post a few weeks later.

The CP 575 cannot be reissued. The IRS won't send you a duplicate, so if you can't find it, you'll need to use one of the other methods below to retrieve your number and request a different verification document going forward. It's worth treating this letter with the same care you'd give your articles of incorporation.

Before you give up on it entirely, do a thorough search. If you applied online, the IRS instructs applicants to print or save the confirmation at the end of the session, so check cloud storage folders, scanned document archives, and any physical files from around the time you formed the business. It turns up more often than people expect once they know where to look. The IRS typically initiates contact by mail rather than email, so an inbox search is unlikely to surface it.

Your business banking account

Opening a business bank account requires an EIN, which means your bank already has it on file. This is often the single fastest way to retrieve your number if you don't have the CP 575 in front of you. Log into your online banking portal and check your account profile. If you already reconcile a bank statement monthly, you may have spotted your EIN there before without realizing it. The original paperwork from when you first figured out how to open a business bank account is another quick option. If none of those surfaces it quickly, a call to your bank's business support line will get it done in minutes since they'll have it tied to your account.

Your accountant or payroll provider

Any CPA or tax preparer who has filed a business return on your behalf has your EIN on every return they've ever prepared. Send them a quick message and expect a fast turnaround. It's not information they need to dig for.

If you run payroll through a third-party provider, your EIN is already sitting in your expense accounts alongside your tax settings. Log in and check your company profile or tax settings. Most platforms surface it within the first few clicks without any phone calls or waiting.

If your accountant is unavailable and your bank records aren't handy, your own tax returns are a reliable backup. Your EIN appears at the top of every business return you've ever filed, and since it never changes once assigned, any prior year works just as well as the most recent one. If you work with a tax preparer and don't keep your own copies, ask them directly. They're required to maintain filed returns and can confirm the number immediately.

Where exactly it appears depends on your business structure. Sole proprietors filing a Schedule C will find it in the top right corner of the form, in box D, labeled "Employer ID number (EIN)." Partnerships and multi-member LLCs filing Form 1065 will see it at the top of page 1 in box D. C corporations filing Form 1120 will find it at the top of page 1 in box B. S corporations filing Form 1120-S will also find it at the top of page 1, but in box D.

If you have employees, Form 941 (the Employer's Quarterly Federal Tax Return) is another strong option. Your EIN appears in the header of page one, clearly labeled, and since it's filed four times a year, recent copies are typically easier to locate than an annual return. Any enterprise expense management platform or HRIS will have electronic copies going back several years.

Your EIN has appeared on more documents over the life of your business than you might expect. If tax returns and bank records aren't accessible, it's worth checking a few other places before picking up the phone. Most businesses have a paper trail that goes back further than they realize.

W-9 forms you've submitted

Every time your business completed a Form W-9 for a client or vendor during onboarding, your taxpayer identification number was listed in Part I. For corporations, partnerships, and multi-member LLCs, that number is the EIN. If your business is a sole proprietorship or a single-member LLC that hasn't elected corporate or partnership tax treatment, the W-9 may show your SSN instead, so it's worth checking what you actually entered before assuming the EIN is there.

With that in mind, this is one of the most commonly overlooked sources, and it's often immediately available. Check your accounts payable vendor files, procurement onboarding records, or any shared drive where your team stores client-facing documents. Many businesses keep a pre-filled W-9 in a shared folder for quick distribution to new clients, which makes retrieval easy.

If your internal records don't surface one, contact a major client or vendor directly. They have the W-9 you submitted during onboarding and can send it back. This is especially useful if your business has changed accounting platforms or moved offices and lost paper records in the process.

Business formation documents

LLC operating agreements and partnership agreements frequently include the EIN in the opening sections where basic business information is defined, but only if they were drafted or amended after the EIN was assigned. One common mistake is checking Articles of Incorporation or Articles of Organization. Those are filed with the state before the EIN exists, so they won't show it.

Stick to post-formation documents instead, things like IRS correspondence, tax filings, account applications, and licenses. Business licenses and local permits are a solid option since most states and municipalities require your EIN on those applications, and it typically appears in the business identification section of the license itself. If you've registered in multiple states, any one of them should work.

IRS notices and correspondence

Most official notices the IRS sends to your business display the EIN near the top of the letter or in the address block. Balance due notices, late payroll filing notices, and income adjustment letters all follow this pattern. Check any IRS mail received at your business address, your registered agent address, or the owner's home address, since the IRS routes correspondence to whatever address it has on file. If you keep a folder of IRS letters, your EIN is almost certainly in there.

Employment and contractor forms

Every W-2 you've issued to an employee shows your business EIN in box b. If you've paid contractors and filed Form 1099-NEC, your EIN appears in the payer information section, and those same filings factor into what business expenses are tax deductible at year-end. The reporting threshold is $600 or more for payments made in 2025 and $2,000 or more for payments made in 2026, so the forms may be more or less common in your records depending on your payment activity.

State unemployment insurance correspondence, quarterly payroll tax reports, and workers' compensation documents are all tied to your EIN. If you're tracking these as part of an LLC expenses cheat sheet, the number will show up across all of them.

Business loan and credit documents

Lenders require your EIN on every loan application and financing agreement, typically within the first two pages. Many of these products also require a personal guarantee, and the EIN appears alongside it in the business identification section. Business lines of credit for startups, equipment financing, and SBA loan paperwork all follow the same pattern. The best business credit cards with EIN only will display it on statements, and if you're a Brex customer, your EIN is tied to your account from the moment you apply.

If you've worked through the options above and still haven't found your number, the IRS has two official channels. Neither delivers results instantly, but both are reliable. What they will give you is certainty, which matters when a lender or institution needs verified confirmation of your EIN.

Call the Business and Specialty Tax Line

The IRS Business and Specialty Tax Line is available Monday through Friday from 7 a.m. to 7 p.m. local time at 800-829-4933. Before you call, have your business's legal name, business address, and your own Social Security number or personal TIN ready. The IRS representative will ask identity verification questions and then provide the EIN over the phone.

Not everyone at your company can make this call. The IRS restricts EIN disclosure to specific authorized parties, including the responsible party named on the original Form SS-4, a third-party designee who was listed on that form at the time of application, or someone with written authorization on file. It's worth knowing that a designee's authority to receive the EIN ends once it's been assigned, so that path only applies during the initial application process.

Written authorization options include Form 2848, which grants Power of Attorney, and Form 8821, which authorizes tax information access. The IRS also recognizes oral disclosure in limited circumstances. If a controller or office manager needs to make this call on behalf of a founder, getting the right authorization documented before an urgent deadline arrives saves real time.

Request Form 147C

During that same IRS phone call, you can request Letter 147C. This is the official EIN verification letter and it functions as a replacement for the CP 575 in most situations where a lender, bank, or institution needs written confirmation of your EIN rather than just the number itself. You can have it faxed to you the same day or mailed within 7 to 14 business days.

If you need to provide written EIN verification to a third party going forward, Letter 147C is what you want. File it alongside your other permanent business records once you receive it. That way, future requests don't require another call to the IRS.

Now that you have it, take ten minutes to store it properly so you're not doing this again in six months. Keep your EIN in at least two secure locations, an encrypted password manager for digital access and a locked physical file alongside your CP 575, formation documents, and any IRS correspondence. That combination means you'll always have a backup if one source becomes inaccessible.

Share your EIN only with parties who have a legitimate reason to ask for it, like banks, payroll providers, government agencies, and vendors who need it for formal tax reporting. It's not a number to include on public-facing materials or marketing documents. Treat it with the same care you'd apply to any sensitive business identifier, because in the wrong hands it can be used to open fraudulent accounts or file false returns in your business's name. If you ever suspect your EIN has been misused, contact a tax professional and report it to the IRS promptly.

Once you have your EIN confirmed, you're ready to set up the financial infrastructure your business actually runs on. That means corporate cards, expense management, and business banking that helps you establish business credit fast without putting your personal assets on the line. To apply with Brex, you'll need your EIN along with company ownership information and owner verification, so having the number ready before you start speeds up the process.

Whether business credit cards affect personal credit depends on which card you choose. Brex reports only to business credit bureaus, keeping your business and personal finances cleanly separated. Once your account is live, you can set up a corporate credit card program, manage expenses, and handle business banking from one place rather than across five separate tools.

Brex is among the best business banking accounts1 for companies that want cards, expenses, and banking managed in one place. Its best-in-class spend management software means finance teams aren't bouncing between platforms to track spending, and the time savings add up fast.

Nick Johnson, VP of Finance at AssemblyAI, described it well. "Brex gives us half a headcount back at our stage, and we expect to save even more at scale." His team saves 5 hours a month on expenses, closes 5 days faster, and runs a 92% reconciliation accuracy rate.

Book a demo or sign up to see how Brex can power your financial operations.

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