How to Form an LLC in Illinois — 2026 Filing Guide

Required?

Yes

Who can serve

Illinois resident individual with a physical IL street address, or a registered Illinois business entity, who is available during normal business hours to accept service of process

Can I serve myself?

Yes

Commercial RA cost

~$125/yr

Self-serving as RA places your home address on the public Illinois SOS record. Commercial RA services ($50–$150/yr) maintain privacy and ensure the Annual Report deadline and other legal mail are not missed.

Renewing or switching? Compare standalone registered agent services — Northwest, Harbor Compliance, Registered Agents Inc., InCorp, and more.

1. Search for name availability through the Illinois SOS Use the Illinois Secretary of State entity name search at apps.ilsos.gov/businessentitysearch/ to confirm your desired LLC name is available. The name must include a valid LLC designator under 805 ILCS 180/1-10. Optional: reserve the name for 90 days ($25) while preparing documents.
2. Appoint an Illinois registered agent Designate a registered agent with a physical Illinois street address (no PO boxes) who is available during normal business hours. Illinois residents with an IL street address may self-serve as RA, but this places your home address on the public SOS record. Commercial RA services ($50–$150/yr) maintain privacy and ensure legal mail is never missed.
3. File Articles of Organization with the Illinois Secretary of State File online at ilsos.gov ($150 fee) or by mail. Provide: LLC name, principal address, registered agent name and IL street address, and organizer signature. Standard online processing: 5–10 business days. Expedited options may be available — check the IL SOS portal for current fees and timeframes.
4. Draft an Operating Agreement Although not required to be filed with the state, an Operating Agreement governs membership percentages, voting rights, profit and loss allocation, member admission and exit rules, and dissolution under 805 ILCS 180/15-5. Chicago-area LLCs with complex business structures should invest in a comprehensive OA — Illinois courts rely on the OA to resolve member disputes.
5. Obtain an EIN from the IRS After Articles are approved, apply for an EIN at irs.gov/ein. The online application takes under 15 minutes and provides the EIN immediately. Print the EIN Confirmation Letter (CP 575) for bank account opening.
6. Register with the Illinois DOR if selling taxable goods or services If your LLC will sell tangible personal property or taxable services in Illinois, register for a Certificate of Registration / Sales Tax Permit at mytax.illinois.gov (free). Illinois's base sales tax rate is 6.25%; local district taxes vary significantly. Chicago's combined rate is approximately 10.25% or higher for certain goods categories. Register before the first taxable sale.
7. Open a business bank account Bring your EIN Confirmation Letter, Articles of Organization, photo ID, and Operating Agreement. Chicago's banking market includes large nationals and regional institutions. A separate business account is the most important step to maintaining the LLC's liability shield.
8. File the Annual Report before the anniversary month each year Illinois LLCs must file an Annual Report and pay the $75 fee before the LLC's anniversary month each year. Filed online through the Illinois Secretary of State portal at ilsos.gov. Failure to file results in dissolution. Calendar the specific anniversary month for this annual compliance obligation.

Illinois Limited Liability Company Act, 805 ILCS 180/1-1 et seq.; Illinois Income Tax Act, 35 ILCS 5/201 (4.95% flat individual income tax); Illinois Corporate Income and Franchise Tax Act, 35 ILCS 5/201(b) (9.5% corporate rate); IRS Rev. Rul. 77-137 on single-member LLC tax treatment.

Direct filing portal: https://www.ilsos.gov/

Formation context

Who should form in Illinois?

Recommended for

Illinois residents and businesses operating primarily in Illinois — especially Chicago, Aurora, Rockford, Joliet, Naperville, and the broader Chicagoland area; Midwest-based small business owners, freelancers, and consultants with Illinois operating nexus; Tech, finance, and professional-services LLCs in the Chicago metro who benefit from Illinois's sophisticated commercial courts and business infrastructure; Logistics, manufacturing, and distribution LLCs in the Chicago/O'Hare/Gary corridor with Illinois operations

Tax treatment (default)

Pass-through by default: single-member LLCs are disregarded entities (Schedule C); multi-member LLCs are partnerships (Form 1065). Illinois imposes a flat 4.95% individual income tax on members' IL-source pass-through income. No franchise tax on LLCs. The 9.5% corporate income tax applies only to entities electing C-corp tax treatment — not to standard pass-through LLCs. Can elect S-corp status (Form 2553) once payroll justifies it.

If you live outside Illinois but are considering forming here, note that Illinois's $150 formation fee and $75/yr annual report offer no particular cost advantage over most peer states. Form in the state where you genuinely operate to avoid paying both Illinois fees and foreign qualification fees in your home state.

No publication requirement in Illinois — unlike New York or Nebraska, you do not need to publish notice in a newspaper after filing.

FAQ

Common Illinois LLC formation questions

Still deciding between an LLC, sole proprietorship, S-Corp, or C-Corp? Our entity-type comparison breaks down formation cost, tax treatment, liability shield, and compliance complexity for all four structures side by side.

Once your LLC clears ~$80K in annual net profit, an S-Corp election (IRS Form 2553) typically saves $5,000–$15,000/year in self-employment taxes by splitting owner income into a W-2 salary + tax-free distributions. The election is free — Form 2553 has no IRS filing fee. The key decision factors: your net income level, a defensible reasonable-compensation salary, and the 75-day Form 2553 filing window after LLC formation.

Already operating as a sole proprietor, or wondering whether a cheap county DBA filing ($10–$100) is enough instead of forming an LLC? A DBA lets you operate under a trade name — but provides zero liability protection. Our DBA vs LLC comparison breaks down exactly when a DBA is sufficient and when you need a state LLC filing.

Missing your annual report deadline triggers late fees and — if left long enough — administrative dissolution, which voids your LLC's liability shield until reinstated. Know your Illinois deadline, fee, and the consequences of missing it.

Also see the LLC annual report requirements hub for state-by-state deadlines, fees, late penalties, and reinstatement rules.

If your LLC opens an office, hires employees, or regularly does business in another state, you must foreign-qualify there — or face fines, back taxes, and loss of standing to sue. Our foreign qualification guide covers when you need it, how to file a Certificate of Authority, and what it costs.

Your Articles of Organization are filed — now make your LLC operational. Four actions every new LLC owner needs to take:

Formation gets your LLC into existence; contracts, trademark protection, operating agreement review, and vendor-document review keep it usable. Compare subscription and per-document legal platforms before you rely on a template or pay a local attorney retainer.

Commingling personal and business funds is the #1 way LLC owners lose their liability shield. A separate business account — in your LLC's legal name, with your EIN — is the foundational act of corporate formality. Mercury, Novo, Bluevine, Relay, and Found open same-day with no monthly fees. Compare online banks vs. Chase and Bank of America.

How you pay yourself depends on your LLC's tax classification — not what you call the transfer. A disregarded single-member LLC pays via owner draw with SE tax on all net profit. An S-Corp-elected LLC splits income between a W-2 salary (FICA applies) and tax-free distributions. Getting this wrong triggers IRS audit risk and SE-tax errors.

Single-member LLCs file Schedule C with their personal Form 1040 (due April 15). Multi-member LLCs file Form 1065 by March 15. S-Corp-elected LLCs file Form 1120-S by March 15. Know your form, your deadline, and the common deductions — home office, vehicle, retirement contributions, and startup costs — before your first April filing.