The CP 575B EIN confirmation notice is the letter the IRS mails to confirm that your business has been assigned an Employer Identification Number. It lists the nine-digit EIN, the legal name on file, your mailing address, and the date the number took effect. The IRS issues this letter only once, which is why banks, accountants, and your own future self will want it stored somewhere safe.
What’s on the Letter
The CP 575B is short and contains four pieces of information you’ll rely on repeatedly:
- The EIN itself, formatted as XX-XXXXXXX. This is the number you’ll put on every federal tax return, payroll filing, and bank application.
- The legal name of the entity exactly as the IRS recorded it from your application. It needs to match your state formation documents and your bank paperwork. Even a small mismatch, like an ampersand where your state filing uses the word “and,” can hold up an account opening.
- The mailing address you gave on your application. The IRS will use it as the default for future correspondence until you change it.
- The effective date the EIN was assigned, which is when you’re considered active in the federal tax system.
Check every field the day the letter arrives. Fixing a wrong name or address now takes a short written request; fixing it mid-filing season, after a mismatch triggers a rejection, takes much longer and can carry penalties.
How and When You Receive It
If you applied online, the IRS issues your EIN immediately on screen and you can print that confirmation right away. The formal CP 575B letter is mailed separately and typically arrives within four to six weeks.1Internal Revenue Service. Get an Employer Identification Number Fax applications on Form SS-4 are generally assigned within four business days with a faxed confirmation; mailed applications take four to six weeks just for initial processing.
The online printout works in a pinch, but some banks and state agencies specifically want the CP 575B or its replacement 147C letter. If you’re trying to open a business bank account quickly, call ahead and ask which the institution will accept.
What You’ll Use It For
Banks ask for the CP 575B because it’s the simplest way to verify that your EIN, legal name, and entity type line up. Without it, most financial institutions won’t open a commercial account in your business’s name.
You’ll also pull the EIN from this letter every time you file a federal return. Corporations enter it on Form 1120,2Internal Revenue Service. Instructions for Form 1120 (2025) – Section: Item B. Employer Identification Number (EIN) and partnerships enter it on Form 1065.3Internal Revenue Service. 2025 Instructions for Form 1065 – Section: Item D. Employer Identification Number (EIN) If you have employees, the EIN goes on your payroll filings as well, including the quarterly Form 941 and the annual Form 940 for federal unemployment tax.4Internal Revenue Service. Form 941, Employer’s QUARTERLY Federal Tax Return
Storing It Safely
Because the IRS issues the CP 575B exactly once, treat it the way you’d treat a deed or an original signed contract. A fireproof safe or a corporate records binder is the right home for the physical copy. Scan it and keep an encrypted digital backup separately, whether that’s a secure cloud service or an off-site drive.
This matters beyond convenience. Your EIN functions like a Social Security number for your business, and anyone who has it can potentially file fraudulent returns or open accounts in your entity’s name. The IRS recommends monitoring your business credit reports for suspicious activity, responding promptly to unexpected IRS notices, and filing a complaint with the FTC if you suspect someone has misused your EIN.5Internal Revenue Service. Tax Practitioner Guide to Business Identity Theft If you believe your EIN has been compromised, file a police report and contact the IRS using the information on the notice that alerted you.
Lost It? Request a 147C Letter
The IRS will not reissue the original CP 575B. What you can get instead is a 147C letter, which serves the same verification purpose and is accepted by banks and other institutions in place of the CP 575B.
Call the IRS Business and Specialty Tax line at 800-829-4933 to request one.6Internal Revenue Service. Telephone Assistance Contacts for Business Customers – Section: Business and Specialty Tax Line and EIN Assignment (800-829-4933) The agent will verify your identity and the business details before issuing the letter. You can have the 147C faxed to you while you’re on the phone, or mailed, which typically takes four to six weeks. If a bank is waiting on documentation, ask for the fax.
The person on the call must be the responsible party listed on the EIN application, or someone the entity has authorized to act on its behalf through a Form 2848 Power of Attorney on file with the IRS.7Internal Revenue Service. Instructions for Form 2848 Power of Attorney and Declaration of Representative If your accountant or attorney will be making the call, get that paperwork in first.
Fixing a Wrong Name or Address
Name
How you correct a name depends on your entity type. Sole proprietors write to the IRS at the address where they’d file their return and explain the correct name. Corporations can check the name-change box on Form 1120 (Line E, Box 3) when they file their next return, or write to the IRS if they’ve already filed. Partnerships do the same on Form 1065 (Line G, Box 3).8Internal Revenue Service. Business Name Change In some situations a name change actually requires a new EIN; IRS Publication 1635 lays out when that applies.
Address
To update the mailing address the IRS has on file, submit Form 8822-B (Change of Address or Responsible Party — Business). Processing generally takes four to six weeks.9IRS. Form 8822-B Change of Address or Responsible Party – Business Until it goes through, IRS correspondence keeps going to whatever address is on your CP 575B, so file promptly after any move.
Keeping the Responsible Party Current
The responsible party is the individual who ultimately owns or controls the entity, with the practical ability to direct its funds and assets.10Internal Revenue Service. Instructions for Form SS-4 (12/2025) For a corporation, that’s typically the principal officer; for a partnership, a general partner; for a trust, the grantor or trustee.
If this person changes, you’re required to report it to the IRS within 60 days using Form 8822-B.9IRS. Form 8822-B Change of Address or Responsible Party – Business This is more than a filing formality. The responsible party is who the IRS contacts about the account and who can call in to request a 147C letter or make changes. If the name on file doesn’t match the person actually running the business, you can find yourself locked out of your own EIN account at the moment you need access most.