How to Start an Illinois LLC — Step by Step

Before anything else, make sure the name you want is free to use. Illinois requires that your LLC name be distinguishable from every other entity already on file with the Secretary of State — not just other LLCs, but corporations, limited partnerships, and reserved names too. "Distinguishable" is a legal standard, so a name that differs only by punctuation, spacing, or a filler word like "the" may still be treated as a conflict.

Run your proposed name through the Illinois business entity search. Search the exact name and close variations. If something too similar already exists, the state can reject your Articles, which costs you the filing turnaround time.

Illinois naming rules

• The name must include "Limited Liability Company," "LLC," or "L.L.C."
• It must be distinguishable from all active and reserved entity names in the state's records.
• It cannot imply an unauthorized purpose or falsely suggest a government agency.
• Words like "bank," "trust," or "insurance" require approval from the relevant Illinois regulator before you can use them.

Reserving a name before you file

If you are not ready to form the LLC yet but want to hold the name, Illinois lets you reserve an available name for a limited period through the Secretary of State. A reservation does not create the LLC; it just keeps the name locked while you handle everything else. Most filers skip this and go straight to the Articles when they are ready.

You need a registered agent decided before you file, because the agent's name and Illinois address go directly on the Articles of Organization. Illinois requires every LLC to keep a registered agent with a physical Illinois street address for the life of the company. The agent receives lawsuits, state compliance notices, and official correspondence on the LLC's behalf.

Who can serve

• Yourself — allowed if you are an Illinois resident with a physical street address (not a P.O. box) and are reliably available during business hours. Your address becomes part of the public record.
• Another individual — any Illinois resident with a street address in the state, such as a co-owner, employee, or attorney.
• A commercial registered agent service — a business that Illinois has authorized to serve in the agent role. It keeps its own address in the public record instead of yours, guarantees availability during business hours, and forwards documents to you.

Why it matters which you pick

Whatever address you list becomes searchable on the state's public entity database. If that is your home, anyone who looks up your LLC finds where you live. Using a commercial service keeps your home address out of the record and removes the risk of missing a lawsuit because no one was at the listed address when a process server showed up.

The Articles of Organization — Form LLC-5.5 — is the filing that legally creates your LLC in Illinois. You file it with the Secretary of State's Department of Business Services, most easily online at apps.ilsos.gov. Filing by mail is available as well, and professional LLCs must file on paper because the online system does not process PLLCs.

Online submissions are the fastest option and typically clear within a few business days; mailed filings take longer. If you are on a deadline, Illinois offers expedited processing for an added state fee.

What the Articles include

• LLC name — your full legal name with the required designator.
• Principal place of business — a physical Illinois-area street address for the company.
• Registered agent name and Illinois street address — the agent's actual physical location, no P.O. boxes.
• Purpose — a general statement is accepted for most businesses.
• Management structure — member-managed or manager-managed.
• Organizer information — the name and address of whoever is filing.
• Effective date — you can request a future effective date if you want the LLC to start on a specific day.

What you do not have to disclose

You are not required to list members' names, ownership percentages, or any financial details on the Articles. It is a short formation document, not a disclosure filing. The internal ownership and money questions live in your operating agreement, which stays private.

An operating agreement is the LLC's internal rulebook. Illinois does not require you to file it with the state, and it never appears in any public database, but you should have one in place before you start doing business or bring in partners.

What a solid operating agreement covers

• Ownership — who the members are and what percentage each holds.
• Capital contributions — what each member put in and any obligation to contribute more later.
• Profit and loss allocation — how gains and losses are split; it usually tracks ownership but does not have to.
• Distributions — when and how cash actually gets paid out to members.
• Management — who runs day-to-day operations and which decisions require a member vote.
• Voting — whether votes are weighted by ownership or counted per member.
• Transfers — what happens when a member wants to sell or leave, including approval and first-refusal rights.
• Dissolution — how the company winds down and how remaining assets are divided.

For a single-member LLC, the agreement helps prove the company is a real separate entity, which matters if anyone challenges your liability protection, and most banks ask to see it. For a multi-member LLC it is essential — without one, the default provisions of the Illinois LLC Act decide these questions for you, and those defaults rarely match what the owners actually intended.

An Employer Identification Number is a nine-digit federal tax ID from the IRS, issued at no cost. Think of it as a Social Security number for the business — you use it on tax filings, to open bank accounts, and to hire employees.

When you need one

• Your LLC has more than one member (multi-member LLCs file a partnership return and require an EIN).
• You plan to hire employees.
• You want to open a business bank account — most banks require it.
• You have elected S-corporation or C-corporation tax treatment.

A single-member LLC with no employees can technically use the owner's Social Security number, but nearly every advisor recommends getting an EIN anyway. It keeps your SSN off business paperwork and streamlines opening accounts.

How to apply

Go to IRS.gov and complete the application in the IRS EIN Assistant. The whole thing runs roughly ten minutes and hands you the number right away, so it's ready to use that same day. You need a valid Social Security number or ITIN to complete the online form. Non-U.S. applicants without one apply by fax or mail using Form SS-4.

Keeping the company's money separate from your own is not optional if you want the liability shield to hold. Paying personal expenses out of the business account, or running business income through your personal account, is exactly the behavior that lets a court disregard the LLC and reach your personal assets.

What banks usually ask for

• Your stamped, filed Articles of Organization
• Your IRS EIN confirmation
• Your operating agreement (many banks require it — have it ready either way)
• Government-issued ID for every authorized signer

Local Illinois community banks and credit unions are often more flexible with brand-new LLCs than large national chains, and several online business banks can open an account without a branch visit. Before you settle on one, weigh the monthly fees, the caps on transactions, and the minimum balances each requires.

Most of the compliance work is front-loaded into formation. After that, the recurring load is light — mainly one annual filing plus staying on top of any changes to your agent or address.

Annual report

Illinois ties the annual report to your formation anniversary rather than a single statewide date. It is due each year before the first day of your LLC's anniversary month, filed online at the LLC annual report portal. It updates your registered agent and address; it is not a financial disclosure. Missing the deadline adds a late penalty, and a long lapse can lead to administrative dissolution.

Registered agent upkeep

If your agent moves, resigns, or you switch to a new one, file the change with the state promptly. A stale registered agent address leaves the LLC technically out of compliance even when everything else is current.

Taxes

Federal filing depends on how the LLC is taxed: single-member LLCs report on Schedule C, multi-member LLCs file Form 1065, and S-corp elections file Form 1120-S. Illinois taxes pass-through income at the member level and imposes the personal property replacement tax on LLC net income — your accountant can handle the specifics. If you sell taxable goods or services, register with the Illinois Department of Revenue for sales tax.

Licenses and permits

Illinois has no single general business license, but many professions require state licensure, and cities like Chicago impose their own business licenses. These run on separate cycles from your LLC registration.