To open a corporation in Illinois, you file Articles of Incorporation (Form BCA 2.10) with the Secretary of State and pay a $150 filing fee. The filing itself can be done online in one sitting once you have a compliant name, a registered agent with a physical Illinois address, and your share structure decided. Standard processing takes roughly five to ten business days, after which the state issues a Certificate of Incorporation and your corporation legally exists.
Formation is only the first step. Before you can bank, hire, or sell anything, you also need a federal EIN and registrations with the Illinois Department of Revenue and, if you’ll have employees, the Department of Employment Security. The full picture is below.
Decisions To Make Before You File
Pick a Name That Will Clear
Every Illinois corporate name must be distinguishable from any other business entity already on file with the Secretary of State. Check availability for free using the Secretary of State’s business entity search before you commit.1Illinois Secretary of State. Business Entity Search
The name must include one of these designators as a separate word or abbreviation: “Corporation,” “Company,” “Incorporated,” “Limited,” or a shortened form like “Corp.,” “Co.,” “Inc.,” or “Ltd.”2Justia. Illinois Compiled Statutes 805 ILCS 5 Article 4 – Name The designator has to stand alone. “Consolidated” doesn’t count as containing “Co.”
One boundary catches people off guard. If you plan to practice a licensed profession such as medicine, law, architecture, engineering, dentistry, or accounting, you cannot form a standard business corporation. Illinois requires those practices to organize under the Professional Service Corporation Act instead, which has its own formation rules and limits on who can hold shares.3Justia. Illinois Compiled Statutes 805 ILCS 10 – Professional Service Corporation Act
Line Up a Registered Agent
Every Illinois corporation must have a registered agent who can accept legal documents and service of process. The agent can be an individual Illinois resident or a business entity authorized to operate in the state, but either way the agent must maintain a physical business office in Illinois that matches the corporation’s registered office address.4Justia. Illinois Compiled Statutes 805 ILCS 5 Article 5 – Office and Agent A P.O. box will not work.
Many owners name themselves to save money, which is fine if you keep consistent business hours at the listed address. If you’d rather not have your home address on the public record, commercial registered agent services run roughly $100 to $300 per year.
Decide on Shares
You’ll need to tell the state how many shares the corporation is authorized to issue and whether those shares carry a par value. Par value is a nominal minimum price written into the articles; it doesn’t reflect actual market worth. Many Illinois corporations use a low par value such as $0.01 per share or designate no par value at all. The authorized number sets the ceiling on how much ownership you can distribute. You don’t have to issue all of it at formation.
Filing the Articles of Incorporation
Form BCA 2.10 is the document that creates your corporation. It’s available as a fillable PDF on the Secretary of State’s website.5Illinois Secretary of State. Form BCA 2.10 – Articles of Incorporation
For corporate purpose, you can state it broadly as “the transaction of any or all lawful business” rather than listing specific activities. Most incorporators use this catch-all so they don’t have to amend the articles later when the business expands.
The incorporator is the person who signs and files the articles. You only need one, and they must be at least 18 years old.6Justia. Illinois Compiled Statutes 805 ILCS 5 Article 2 – Formation of Corporations The incorporator doesn’t have to be a future owner or director; an attorney or formation service can play that role. The form also asks for initial directors, who manage the corporation until the first shareholder meeting. Naming at least one on the articles is standard.
You can submit online through the Secretary of State’s electronic filing portal or mail paper articles to the Department of Business Services at 501 S. Second Street, Room 350, Springfield, IL 62756. The base filing fee is $150.7Illinois Secretary of State. Domestic and Foreign Corporations Publications and Forms Online filers pay by credit card; mail filings need a check or money order payable to the Secretary of State.
Illinois has historically charged an initial franchise tax on top of the filing fee, calculated from paid-in capital, but the state has been phasing it out with increasingly large exemptions. For a new corporation with modest capitalization in 2026, the initial franchise tax will likely be zero or close to it. Check the current fee schedule before you file, since the exemption amounts change annually.
Standard processing takes roughly five to ten business days. Expedited 24-hour processing is available for an additional $100.8Illinois Secretary of State. Department of Business Services Once approved, you receive a Certificate of Incorporation with an official file number. That certificate is your proof the corporation exists.
Registrations To Complete After the Certificate Issues
Federal EIN
You need a federal Employer Identification Number from the IRS before you can open a business bank account, hire employees, or file tax returns. The application is free and takes about ten minutes online. You’ll need the Social Security number or ITIN of a responsible party, usually an officer or owner, and the EIN issues immediately on approval.9Internal Revenue Service. Get an Employer Identification Number
Illinois Department of Revenue
Any corporation doing business in Illinois must register with the Illinois Department of Revenue before making sales, purchases, or hiring. Register online through MyTax Illinois or mail Form REG-1. Paper takes four to six weeks; online is much faster.10Illinois Department of Revenue. Business Registration
Unemployment Insurance
If you’ll have employees, register with the Illinois Department of Employment Security within 30 days of starting operations. This is separate from the Department of Revenue registration. Register electronically through MyTax Illinois or submit Form REG-UI-1.11Illinois Department of Employment Security. Are You a New Employer?
S-Corp Election (Watch the Deadline)
A new Illinois corporation is taxed as a C-corporation by default. If you want pass-through tax treatment, with profits and losses flowing to your personal return instead of being taxed at the corporate level, file IRS Form 2553 to elect S-corporation status. The window is narrow: no more than two months and 15 days after the corporation’s first tax year begins.12Internal Revenue Service. Instructions for Form 2553 Miss it and you’re a C-corp for the full first year.
Bylaws, Organizational Meeting, and Records
Shortly after approval, the initial directors should hold an organizational meeting. This handles the setup that makes the corporation functional: adopting bylaws, appointing officers, authorizing a bank account, and recording the initial issuance of shares. None of this gets filed with the state, but it needs to happen and be documented in the minutes.
Bylaws are the corporation’s internal operating rules, covering director elections, officer roles, how meetings are called and conducted, and how votes are counted. Illinois doesn’t require you to file bylaws with the Secretary of State, but you are required to have them.
Illinois law also requires every corporation to keep accurate books, minutes of shareholder and board meetings, and a shareholder record showing names, addresses, and holdings. These must be kept at the registered office, the principal Illinois place of business, or the office of the transfer agent or registrar in the state. Skipping these formalities is how corporations lose liability protection: courts can pierce the corporate veil and hold owners personally liable when the separation between corporation and owners stops looking real.
Keeping the Corporation in Good Standing
Every Illinois domestic corporation must file an annual report with the Secretary of State. It’s due before the first day of the corporation’s anniversary month, meaning the month in which the articles were originally filed. The report updates officer, director, and registered agent information and carries the franchise tax payment (which, as above, may well be zero).
If you miss it, the Secretary of State mails a Notice of Delinquency to your registered office. You then have 90 days to correct the problem. If you don’t, the Secretary of State can administratively dissolve the corporation.13Illinois General Assembly. Illinois Compiled Statutes 805 ILCS 5/12.40 – Procedure for Administrative Dissolution Dissolution terminates the corporation’s legal existence. It can’t do business, enter contracts, or sue. Reinstatement is possible but requires paying all back fees and penalties. A calendar reminder is the easiest fix.
Changing the Articles Later
If you need to change the corporate name, adjust authorized shares, or modify the stated purpose, you file Articles of Amendment with the Secretary of State. The filing fee is $50.14Illinois General Assembly. Illinois Compiled Statutes 805 ILCS 5/15.10 Before any shares are issued, a majority of the board can approve the amendment. Once shares are outstanding, amendments generally require a board resolution plus shareholder approval, typically a two-thirds vote unless your articles set a different threshold. Amendments are filed in duplicate. A restated set of articles, which consolidates all prior amendments into one document, costs $150 instead of $50.