The difference between an LLC number and an EIN comes down to which government issued it. Your LLC number is a state identifier assigned by the Secretary of State (or equivalent filing office) when it approved your Articles of Organization. Your EIN, or Employer Identification Number, is a federal tax ID assigned by the IRS. Different agencies, different purposes, and you can’t substitute one for the other on a form.
What the LLC Number Is
When your state approves your LLC formation, the filing office stamps an identifier on the paperwork. Depending on where you filed, it might appear as a Charter Number, Entity ID, File Number, or Control Number. It has no federal tax significance.
The state uses this number to track your company’s legal standing: whether you’ve filed annual reports, paid any required franchise taxes, and remain in good standing to transact business. Formation fees to receive one range from roughly $50 to over $500 depending on the state, and most states charge a recurring annual or biennial report fee to keep the number active. Letting those filings lapse can trigger administrative dissolution, which ends the LLC’s legal existence and can expose the owners personally to business debts.
If you later register the same LLC to do business in a second state (foreign qualification), that state issues its own separate entity number. One company, two state IDs. Your EIN, however, stays the same everywhere.
What the EIN Is
An EIN is a nine-digit number formatted XX-XXXXXXX that the IRS assigns to business entities for federal tax purposes.1Cornell Law School. Employer Identification Number (EIN) It functions like a Social Security Number for your company, letting the IRS tie every return, employment filing, and reporting obligation back to the right business.
Its usefulness runs past taxes. Banks require an EIN to open an account in the LLC’s legal name. Vendors ask for it on Form W-9. Business credit bureaus such as Dun & Bradstreet and Experian Business use it to build your company’s credit file, which is how you keep business credit history separate from your personal credit.
Once issued, the EIN belongs to that entity permanently. The IRS won’t cancel it or reassign it to another business. If you close the LLC, you can ask the IRS to deactivate the account, but the number itself is never recycled.2Internal Revenue Service. If You No Longer Need Your EIN
Side by Side
The two numbers answer different questions. Your state entity number answers: is this LLC properly registered and in good standing? Your EIN answers: which taxpayer is this federal filing attached to?
Use the state entity number on Secretary of State filings (formation documents, annual reports, amendments). Use the EIN on federal tax returns, payroll filings, W-9s, and bank applications. Mixing them up on filings is one of the more common compliance errors new owners make.
There is also a third number many owners don’t anticipate. If your state collects income, sales, or employment taxes, its department of revenue (a separate agency from the Secretary of State) issues its own state tax ID.3U.S. Small Business Administration. Get Federal and State Tax ID Numbers So an active LLC can carry three distinct numbers from three different agencies, each with its own purpose.
Does Your LLC Actually Need an EIN?
Not every LLC is legally required to get one. A single-member LLC with no employees and no excise tax liability can technically use the owner’s SSN for federal tax purposes.4Internal Revenue Service. Single Member Limited Liability Companies Most still apply for one anyway, to keep the owner’s SSN off vendor forms and bank paperwork.
An EIN becomes mandatory as soon as any of these apply:
- The LLC has two or more members. A multi-member LLC is treated as a partnership for federal tax purposes and must file Form 1065, which requires an EIN.
- The LLC hires employees. Even one worker triggers payroll tax withholding and quarterly Form 941 filings. A single-member LLC that is otherwise a disregarded entity must use its own EIN, not the owner’s SSN, for employment tax reporting.4Internal Revenue Service. Single Member Limited Liability Companies
- The LLC elects to be taxed as an S-corp (Form 2553) or C-corp (Form 8832), regardless of member count.5Internal Revenue Service. About Form 2553, Election by a Small Business Corporation
- The LLC operates a qualified retirement plan or is liable for excise taxes (such as those on alcohol, tobacco, or firearms).
For a disregarded single-member LLC without any of these triggers, business income flows onto Schedule C, E, or F of the owner’s Form 1040 under the owner’s SSN. That setup works, right up until employment or excise taxes enter the picture.
Getting an EIN
The IRS issues EINs for free through its online application. It takes about ten minutes and the number is assigned immediately on approval. Any site charging you for this is adding a fee the government doesn’t.6Internal Revenue Service. Get an Employer Identification Number
Form the LLC with your state first. The IRS doesn’t ask for your state entity number on the application, but it recommends completing state formation beforehand to avoid processing problems. You’ll need the LLC’s legal name, its physical address, and the SSN or ITIN of the responsible party.
The responsible party must be an individual, not another entity. The IRS defines this as the person who ultimately owns or controls the LLC and has practical authority over its funds and assets.7Internal Revenue Service. Instructions for Form SS-4 (12/2025) For a single-member LLC, that’s the owner; for a multi-member LLC, it’s typically the managing member.
The online application is available Monday through Friday from 6:00 a.m. to 1:00 a.m. Eastern, Saturday from 6:00 a.m. to 9:00 p.m., and Sunday from 6:00 p.m. to midnight. It can’t be saved and times out after 15 minutes of inactivity, so finish it in one sitting. The IRS limits each responsible party to one EIN per day. If you prefer paper, faxing Form SS-4 produces an EIN in about four business days; mailing it to the IRS in Cincinnati takes roughly four weeks.8Internal Revenue Service. Employer Identification Number
Keeping Both Numbers Alive
Your EIN carries one maintenance obligation most owners miss. If the responsible party on file with the IRS changes, you must file Form 8822-B within 60 days of the change. That covers situations like a managing member being replaced or an LLC being sold.9Internal Revenue Service. Form 8822-B, Change of Address or Responsible Party
Your state entity number stays valid only as long as you meet the state’s filing requirements. Annual or biennial reports keep it active; fees range from nothing in a few states to several hundred dollars elsewhere. Miss them and you’re looking at late penalties, and eventually administrative dissolution.
Lost Your EIN?
It happens, especially for businesses that don’t file often. Check the IRS confirmation notice (CP 575) sent when the number was first issued, a prior year’s business return, your business bank, or any state or local licensing agency where you used it. If none of that turns it up, call the IRS Business & Specialty Tax Line at 800-829-4933 between 7:00 a.m. and 7:00 p.m. local time, Monday through Friday. After an identity check, they’ll give the number over the phone, and you can request a formal confirmation (Letter 147C) if a lender or agency needs one in writing.8Internal Revenue Service. Employer Identification Number