Is an Illinois EIN Different From a Federal EIN?
No. The EIN is federal, so an Illinois EIN and a federal EIN are the same 9-digit number. Illinois does not issue its own EIN. The IRS assigns 1 number, for $0, that works in all 50 states.
| State | Issues its own EIN? | Number the business uses | IRS fee |
|---|---|---|---|
| Illinois | No | Federal 9-digit EIN | $0 |
| Texas | No | Federal 9-digit EIN | $0 |
| Florida | No | Federal 9-digit EIN | $0 |
| All 50 states | No | 1 federal EIN each | $0 |
Source: IRS Form SS-4 instructions and 26 U.S.C. section 6109, verified August 2026.
Because the EIN is issued under federal statute, the IRS process is identical for an Illinois applicant and a California applicant: the same Form SS-4, the same $0 fee, and the same CP-575 confirmation letter. Reclassifying how an Illinois LLC is taxed, using Form 8832, or electing S-corporation status with Form 2553, keeps the same 9-digit EIN. The federal number and the process behind it are detailed on the IRS EIN number page.
An Illinois applicant and a New York applicant receive numbers from the same IRS pool, and neither number carries a state prefix. The first 2 digits, once tied to a filing campus, no longer map to any 1 state. A business that moves from Illinois to Texas keeps its original 9-digit EIN and files no new SS-4. The 1 exception is a change of entity type, such as a sole proprietor incorporating, which draws a fresh EIN. For the LLC-specific route, the how to get an EIN for an LLC page walks each of the 4 methods.
What Is the Difference Between an EIN and an Illinois State Tax ID?
The EIN is the 9-digit federal number from the IRS. An Illinois state tax account is separate: a business registers with the Illinois Department of Revenue through MyTax Illinois for sales tax and payroll withholding. They are 2 different numbers, and both cost $0.
| Identifier | Issued by | Purpose | Cost |
|---|---|---|---|
| Federal EIN | IRS | Federal tax, payroll, banking | $0 |
| Illinois tax account | Illinois Dept of Revenue via MyTax Illinois | Sales and withholding tax | $0 |
| Illinois sales tax permit | Illinois Dept of Revenue | Collect the 6.25% state sales tax | $0 |
Source: Illinois Department of Revenue, MyTax Illinois registration, verified August 2026.
Most Illinois businesses obtain the EIN first, because the Illinois registration form asks for the federal 9-digit number. A retailer that sells taxable goods registers to collect the 6.25% state sales tax; an employer registers to withhold the flat 4.95% income tax from wages. Neither Illinois registration replaces the EIN. The single-owner case, where 1 SSN can stand in for federal filing, is covered on EIN for a single-member LLC.
An Illinois retailer that ships statewide collects the 6.25% base rate, and a Chicago storefront collects 10.25% once city and county add-ons stack on top. The federal EIN stays 1 number through all of it. Registration on MyTax Illinois is free, takes under 20 minutes, and reuses the same 9-digit EIN the IRS already issued for $0. An employer registers a second Illinois account to withhold the flat 4.95% income tax from each of its workers' paychecks.
No SSN. No passport upload.
How Do You Get an EIN in Illinois?
There are 4 ways: online in 15 minutes with an SSN, by fax in 4 to 7 business days, by mail in 6 to 11 weeks, or by phone for international applicants. All 4 cost $0 at the IRS, and none is Illinois-specific.
| Method | Time to EIN | SSN needed? | IRS fee |
|---|---|---|---|
| IRS online assistant | About 15 minutes | Yes | $0 |
| Fax Form SS-4 | 4 to 7 business days | No | $0 |
| Mail Form SS-4 | 6 to 11 weeks | No | $0 |
| Phone, international only | On the call | No | $0 |
Source: IRS Form SS-4 instructions, verified August 2026.
The online assistant runs Monday to Friday, 7 a.m. to 10 p.m. Eastern, and validates the applicant against SSN and ITIN records, so it stops anyone who holds neither. Those applicants enter the word Foreign on Form SS-4 line 7b and fax the form to 855-641-6935 within the US, or 855-215-1627 from abroad. The IRS international line, 267-941-1099, releases the number on the call. The online path is walked through on apply for an EIN online.
Every Illinois applicant files the same 1-page Form SS-4 regardless of method, and the IRS returns the CP-575 confirmation letter as proof of the assigned number. The fax numbers 855-641-6935 and 855-215-1627 run 24 hours a day, and a faxed SS-4 that lists a return fax number comes back within 4 to 7 business days. A single responsible party signs the form, and the IRS caps issuance at 1 EIN per responsible party per day. The Texas EIN process is identical, because both states share the 1 federal system.
What Illinois Taxes Apply to a New Business?
Illinois taxes business income at a flat 4.95%, with no brackets. Sellers collect a 6.25% state sales tax, and every LLC files a $75 annual report each year. A corporation adds a 2.5% replacement tax on top of its income tax.
| Illinois tax | Rate or fee | Agency |
|---|---|---|
| Individual income tax (flat) | 4.95% | Illinois Dept of Revenue |
| Corporate income tax | 7% | Illinois Dept of Revenue |
| State sales tax (general merchandise) | 6.25% | Illinois Dept of Revenue |
| Chicago combined sales tax | 10.25% | State plus local |
| Corporate replacement tax | 2.5% | Illinois Dept of Revenue |
| LLC annual report | $75 | Secretary of State |
Source: Illinois Department of Revenue rate schedules, verified August 2026.
The flat 4.95% rate means a $50,000 profit and a $500,000 profit face the same percentage, with no graduated brackets. A corporation pays 7% corporate income tax plus the 2.5% replacement tax, a combined 9.5%. Sales tax starts at the 6.25% state rate and reaches 10.25% in Chicago once local add-ons apply. None of these state taxes touches the federal EIN, which stays free and unchanged. The full federal cost picture sits on LLC EIN cost.
A 5-employee Illinois shop withholds the flat 4.95% from each paycheck and remits it to the Illinois Department of Revenue, an obligation entirely separate from the $0 federal EIN. The 2.5% replacement tax dates to 1979 and funds local government units. None of these 3 state layers changes the single federal number issued under 26 U.S.C. section 6109, which the business keeps for its full life at no renewal cost.
What Does an Illinois LLC Cost?
An Illinois LLC costs $150 to form, paid once for the Articles of Organization, plus a $75 annual report each year. The federal EIN adds $0. einforllc.co files Form SS-4 for applicants with no SSN for $97.
| Item | Cost | Frequency |
|---|---|---|
| Articles of Organization filing | $150 | One-time, Secretary of State |
| Illinois LLC annual report | $75 | Every year |
| Federal EIN at the IRS | $0 | One-time |
| einforllc.co filing — Standard | $97 | Faxed within 7 business days |
| einforllc.co filing — Fast | $127 | Filed within 24 hours |
| Year 2 EIN renewal | $0 | An EIN never renews |
Illinois LLC fees under the Illinois Limited Liability Company Act, 805 ILCS 180, verified August 2026.
A first-year Illinois LLC run by an owner with an SSN pays $150 to the Secretary of State and $0 to the IRS, for a $150 federal-and-formation total. An owner with no SSN cannot use the free online tool and pays einforllc.co $97, or $127 within 24 hours, on top of the $150 state fee. From year 2 on, the recurring cost is the $75 annual report. A Texas or Florida comparison sits on EIN number in Florida.
This page states federal and Illinois tax rules current as of August 2026. It is not legal or tax advice. Confirm your business's position with a licensed CPA or attorney before filing.