If your out-of-state company is doing regular business in Illinois, you register as a foreign entity with the Illinois Secretary of State before that activity begins. Illinois foreign entity registration produces a certificate of authority for a corporation or a certificate of admission for an LLC, gives you the right to sue in Illinois courts, and shields you from the escalating penalties that hit unregistered businesses. The base filing fee is $150 for both entity types, and the paperwork differs mainly in what supporting documents you need to attach.
When Registration Is Required
Not every contact with Illinois triggers registration. Section 13.75 of the Business Corporation Act sets out a safe harbor for foreign corporations, and Section 45-47 of the LLC Act does the same for LLCs.1Illinois General Assembly. Illinois Code 805 ILCS 5 – Business Corporation Act of 1983 – Section 13.75 You can do all of the following without registering:
- Defend or settle a lawsuit in Illinois court.
- Hold internal board or shareholder meetings in the state.
- Maintain an Illinois bank account.
- Sell through independent contractors.
- Solicit orders from Illinois customers that require acceptance outside the state.
- Own Illinois real estate or personal property, with nothing more.
- Complete an isolated transaction within 120 days that isn’t part of a recurring pattern.
- Have an officer or director who happens to live in Illinois.
You cross into registration territory when your presence becomes continuous. Opening an office or warehouse, hiring Illinois-based employees, or entering into a pattern of recurring contracts with Illinois customers all point that way. The Secretary of State weighs the overall pattern, not any single factor.
How Corporations Register
Foreign corporations file Form BCA 13.15, the Application for Authority to Transact Business in Illinois.2Illinois General Assembly. Illinois Code 805 ILCS 5/13.15 – Application for Authority The form asks for:
- Your corporation’s exact legal name as it appears in your home state’s records.
- The state and date of incorporation.
- The address of your principal office.
- The names and addresses of all current officers and directors.
Every detail has to match your home-state records. A name variation, a wrong formation date, or an outdated principal address will get the application returned. Corporations do not need to attach a certificate of good standing, which is one place where the corporate filing is simpler than the LLC version.
How LLCs Register
Foreign LLCs file Form LLC 45.5, the Application for Admission to Transact Business.3Illinois General Assembly. Illinois Code 805 ILCS 180/45-5 – Application for Admission The form covers the same basic ground as the corporate application, plus a few items specific to LLCs:
- Whether the LLC is manager-managed or member-managed.
- The purposes for which the LLC was organized.
- A statement appointing the Secretary of State as agent for service of process in certain circumstances.
LLCs must also include a certificate of good standing (sometimes called a certificate of existence) from their home state, dated within 60 days of the Illinois filing. Order it too early and it goes stale before you file, forcing you to request a fresh one. The certificate has to come from whichever office keeps LLC records in your home jurisdiction.
Registered Agent
Both corporations and LLCs must designate an Illinois registered agent with a physical street address in the state. A P.O. box will not do; the agent has to be reachable for in-person service of process during business hours. The agent can be an Illinois resident, a domestic Illinois corporation, or a foreign corporation already authorized to do business in Illinois. If the agent is a corporation, its articles of incorporation must specifically allow it to serve in that role.3Illinois General Assembly. Illinois Code 805 ILCS 180/45-5 – Application for Admission
Many out-of-state businesses hire a commercial registered agent service. Annual costs typically run between $49 and $125.
Filing Fees and Processing
The base filing fee is $150 for both foreign corporations and foreign LLCs. LLCs can file online through the Secretary of State’s portal, which usually moves faster than paper. Corporations generally file by mail or in person at the Springfield office. Payment goes by check payable to the Illinois Secretary of State. No cash.
Standard processing can take several weeks depending on filing volume. Expedited processing is available for an additional $100 for corporations and is worth it when you need the certificate to close a deal or sign a lease.4Illinois Secretary of State. Expedited Service Fees
Franchise Tax Phase-Out
Foreign corporations historically owed an initial franchise tax based on paid-in capital allocated to Illinois. Illinois has been phasing that tax out. The exemption threshold rose to $10,000 in liability as of 2025, and the tax is eliminated entirely for 2026 and later tax years.5Illinois General Assembly. Illinois Code 805 ILCS 5/15.65 – Additional Franchise Tax Most foreign corporations registering now will owe no franchise tax with their application, but confirm current status with the Secretary of State before filing since older forms and guides may still reference it.
Name Availability
Your legal name has to be distinguishable from every other entity already on the Illinois Secretary of State’s rolls. If someone in Illinois has your name, you can’t just push the filing through. Check the Secretary of State’s business name database before submitting.
The LLC statute specifically allows a foreign LLC to transact business under a name different from its legal name.3Illinois General Assembly. Illinois Code 805 ILCS 180/45-5 – Application for Admission Both corporations and LLCs in good standing can also formally adopt an assumed name through a separate filing with the Secretary of State, which carries its own fee.6Illinois Secretary of State. Adopting an Assumed LLC Name
Penalties for Skipping Registration
Doing business in Illinois without registering carries real consequences, and they hit LLCs harder than corporations.
Corporations
An unregistered foreign corporation cannot file or maintain a lawsuit in any Illinois court until it registers. The corporation also owes all the fees and taxes it would have paid on time. If registration doesn’t happen within 60 days of starting Illinois operations, an additional penalty applies: 10% of the fees and taxes owed, or $200 plus $5 per month of unregistered activity, whichever is greater. The Attorney General can sue to collect. An unregistered foreign corporation is also deemed to have consented to general jurisdiction in Illinois, so Illinois courts can hear any case against it, not just cases connected to its Illinois activity.7Justia Law. Illinois Code 805 ILCS 5 – Article 13 – Foreign Corporations
LLCs
Foreign LLCs face the same court-access bar and steeper financial penalties. An LLC that doesn’t register within 60 days of starting Illinois business owes $2,000 plus $100 for each month it continues operating without admission. The Secretary of State also automatically becomes the LLC’s agent for service of process, so a plaintiff could sue you and serve papers on a state office instead of your actual business address. If you’re not paying attention, the first news you get of a lawsuit may be a default judgment.8Illinois General Assembly. Illinois Code 805 ILCS 180 – Limited Liability Company Act – Section 45-45
One point of relief for both entity types: failing to register does not invalidate your contracts or prevent you from defending a case someone else brings against you. Existing deals remain enforceable. But losing the ability to bring your own claims in Illinois courts cripples collections and contract enforcement.
After You’re Registered
Registration is not one-and-done. Foreign corporations file an annual report on Form BCA 14.05. The filing fee is $75, with an optional $50 expedited processing fee.9Illinois Secretary of State. Domestic and Foreign Corporations Publications and Forms The report updates officers, directors, registered agent, and principal office. Miss the deadline and you face penalties and, eventually, involuntary revocation of your certificate of authority.
Foreign LLCs have their own annual reporting obligation. In either case, keep the registered agent information current throughout the year, because a stale address is how service of process goes missing.
When you actually stop doing business in Illinois, file a formal withdrawal rather than letting the registration lapse. Foreign LLCs use Form LLC-45.40, which costs $5 to file, surrenders the admission, and consents to future service of process through the Secretary of State.10Illinois Secretary of State. Application for Withdrawal – LLC 45.40 Foreign corporations follow a parallel withdrawal process through the Secretary of State’s business services division. Withdrawal stops future annual report obligations, but it does not erase liabilities that arose while you were operating in the state.