Key takeaways
- LLC filing fee: $150 — filed with the Illinois Secretary of State Business Search.
- Processing time: 5-10 business days (expedite available for +$50).
- Annual report: Required — $75, due Anniversary of formation.
- Name reservation: $25 — Name reservation fee is $25 and holds the name for 90 days.
- State income tax: Flat 4.95%.
Is your business name available?
Checks Illinois entity records plus matching domain availability — we never store your search.
How to search Illinois business entities
Searching Illinois business records is straightforward. The Illinois Secretary of State Business Search is the authoritative registry for every entity formed or registered in the state, and it handles roughly 15,926 new applications a month (modeled estimate). Follow these steps to look up any registered LLC, corporation, or partnership in Illinois.
Open the official Illinois portal
Click the button below to open the Illinois Secretary of State Business Search in a new tab. This is the same database used by Illinois attorneys and compliance officers, and it is updated as filings are processed (5-10 business days standard).
Type the business name
Enter the full or partial company name. Most searches are case-insensitive. If the name is common in a state of 12.55M residents, add the city or registered agent to narrow results.
Read the result record
The result will show the entity's status (Active, Inactive, Dissolved), formation date, registered agent, and principal office address. The entity number is shown in the upper-right of the record.
Download the certificate (optional)
Most Illinois records can be downloaded as a PDF certificate of existence — useful for opening a business bank account, securing a loan, or proving entity status to a third party.
Check the annual report
While you're in the record, check the date of the last annual report (due Anniversary of formation). If it's overdue, the entity may be in danger of administrative dissolution.
Save or print
Bookmark the result or print the certificate for your records. Lenders and licensing boards usually ask for a recent certificate — within the last 90 days.
Open Illinois official search →
Illinois filing facts
Key numbers to know before you form or maintain an Illinois business entity. These are the fees and deadlines published by the Illinois Secretary of State Business Search.
How much does it cost to form an LLC in Illinois?
The total cost of forming an Illinois LLC depends on which extras you need. Here is the full breakdown based on the current fee schedule published by the Illinois Secretary of State Business Search:
| Item | Cost | Required? |
|---|---|---|
| Articles of Organization filing fee | $150 | Yes |
| Expedited processing (24 hours) | +$50 | Optional |
| Name reservation (optional) | $25 | Optional |
| Annual report / recurring fee | $75 per year | Yes (ongoing) |
| First-year total (standard filing) | $225 | — |
| Estimated 5-year total cost | $525 | — |
Watch for the franchise tax: A franchise tax applies to corporations. This is separate from the filing fee and catches many new owners off guard — factor it into your real first-year cost.
These figures cover the state filing fee only. If you hire a formation service or a registered agent, add their service charge on top. For a side-by-side comparison of every state, use our LLC Cost Calculator.
How Illinois compares to other states
Here is where Illinois stands among all 51 jurisdictions, based on the fee schedules and processing times we track:
For context, the cheapest state to form an LLC is Kentucky at $40, while the most expensive is Massachusetts at $500. Illinois's $150 filing fee puts it $21 above that national average. Founders here pay a premium, so weigh the state's business climate and market access against the higher fee. Keep the recurring $75 report in mind when comparing long-term costs.
Business entity types available in Illinois
Illinois recognizes several business structures, with filing fees ranging from $150 for an LLC to $150 for a corporation. Choosing the right one affects your liability protection, tax treatment, and ongoing paperwork. Here are the most common options:
LLC
Limited Liability Company — the most popular choice for small businesses. Combines liability protection with flexible, pass-through taxation. Filing fee: $150.
Corporation (C-Corp)
A separate legal entity that can issue stock. Subject to corporate income tax, but ideal for raising venture capital. Filing fee: $150.
S-Corporation
A tax election (not a separate entity type) that lets profits pass through to owners, avoiding double taxation. File Form 2553 with the IRS after forming a corp or LLC.
Partnership
General and limited partnerships for two or more owners. Simpler to form but offers less liability protection than an LLC unless structured as an LP or LLP.
Sole Proprietorship
The simplest structure — no formal filing required. However, the owner is personally liable for all business debts. Best for low-risk, single-owner operations.
Foreign Entity
Already registered in another state? Register as a foreign entity in Illinois for $150 to legally operate here.
How to form an LLC in Illinois
Forming an Illinois LLC takes a handful of steps. Most owners complete the paperwork in a single afternoon, and the state approves filings in 5-10 business days — or faster with the $50 expedited option.
Choose a compliant name
Your name must be distinguishable from existing Illinois entities and include a designator like "LLC" or "Limited Liability Company". Use the search tool above to check availability first.
Appoint a registered agent
Every Illinois LLC needs a registered agent with a physical address in the state. You can serve as your own agent or hire a commercial service for privacy.
File the Articles of Organization
Submit the formation document to the Illinois Secretary of State Business Search and pay the $150 filing fee. Most states accept online filing, which is faster than paper.
Create an operating agreement
Not always required by the state, but an operating agreement defines ownership percentages, profit splits, and management rules. Banks and investors often ask for one.
Get an EIN from the IRS
Apply for a free Employer Identification Number at IRS.gov. You'll need it to open a business bank account, hire employees, and file taxes.
Handle state & local registrations
Register for state taxes, sales tax permits, and any local business licenses your city or county requires. Requirements vary by industry and location.
Illinois business tax overview
Understanding Illinois's tax landscape helps you plan cash flow and choose the right entity structure. Here are the key state-level taxes that affect Illinois businesses:
Note: Illinois also imposes a personal property replacement tax on pass-through entities.
LLCs are typically pass-through entities, meaning profits flow to the owners' personal tax returns rather than being taxed at the entity level. However, some states impose entity-level taxes or fees regardless of structure. Always confirm current rates with the Illinois Department of Revenue or a licensed tax professional before making decisions.
Illinois-specific rules and gotchas
Illinois has a few rules that surprise new business owners. Here is what to watch for before you file.
- Illinois charges an additional $50 "franchise tax" for corporations in the year of formation.
- If you file your annual report late, you are charged a $100 penalty for LLCs.
- Foreign LLCs must qualify before doing business in Illinois.
Pro tips for Illinois entity searches
These tips come from Illinois registered agents, paralegals, and CPAs who run hundreds of searches a year.
- Illinois annual report fee is $75 for both LLCs and corporations.
- You can file online through the Illinois Secretary of State portal.
- Expedited service is available for $50 extra.
Renewals and ongoing compliance in Illinois
LLCs file an annual report ($75) before the first day of the anniversary month.
Missing a renewal deadline is the most common way Illinois businesses get administratively dissolved or lose good standing. Set a calendar reminder well before the due date, and confirm the current deadline on the official portal below.
Check Illinois renewal status →
Illinois annual report: fee, deadline, and penalties
LLCs file an annual report ($75) before the first day of the anniversary month.
How to file: Most Illinois reports can be filed online through the Illinois Secretary of State Business Search. Log in, confirm your entity information is current, and pay the fee. Keep a copy of the confirmation for your records.
What happens if you miss it: If the report is not filed on time, Illinois can assess the late penalty listed above and eventually administratively dissolve or revoke your LLC. A dissolved entity loses its liability protection and its legal right to do business in the state, and you will need to file a reinstatement (which costs more than simply filing on time). Set a calendar reminder a few weeks before the due date so you never miss it.
Certificate of Good Standing in Illinois
A Certificate of Good Standing — also called a certificate of existence or certificate of status — is an official document from the Illinois Secretary of State Business Search confirming that your business is legally registered, active, and current on its required filings. Banks, lenders, and other states treat it as proof that your entity is legitimate.
When you need one:
- Opening a business bank account or applying for a business loan.
- Registering your Illinois entity as a foreign LLC in another state.
- Renewing certain professional or industry licenses.
- Closing a real estate transaction or signing a large contract where the other party verifies your status.
How to get it: Order the certificate through the Illinois Secretary of State Business Search — most states let you request it online and download a PDF instantly, or mail you a certified paper copy. There is usually a small fee, and the entity must be current on its annual report (due Anniversary of formation) to qualify. If your entity is not in good standing, file any overdue reports first, then request the certificate.
LLC vs. corporation in Illinois
Both structures limit personal liability, but they differ in taxation, governance, and suitability. Here's a quick comparison to help you decide:
| Factor | LLC | Corporation |
|---|---|---|
| Formation fee | $150 | $150 |
| Taxation | Pass-through by default | Corporate tax (C-Corp) or pass-through (S-Corp election) |
| Governance | Flexible — operating agreement | Formal — board, officers, bylaws, annual meetings |
| Raising capital | Harder — no stock | Easier — can issue shares |
| Paperwork | Minimal | More record-keeping required |
| Best for | Small businesses, freelancers, real estate | Startups seeking investors, larger companies |
For most small-business owners in Illinois, the LLC is the simpler and more tax-efficient choice. If you plan to seek venture funding or go public, a corporation (usually a Delaware C-Corp) is the standard path.
Who uses Illinois business entity search?
The official Illinois entity database is not just for business owners. With 12.55M residents and 132,900 new businesses formed in 2023, a wide range of professionals and everyday users rely on it:
- Entrepreneurs and founders check whether a desired business name is available before filing formation documents.
- Attorneys and paralegals verify entity status, registered agents, and good standing during transactions, litigation, and due diligence.
- Lenders and banks confirm a borrower's legal existence and status before approving business loans or lines of credit.
- Landlords and property managers verify that a prospective commercial tenant is a real, active entity before signing a lease.
- Journalists and researchers trace ownership, find registered agents, and investigate corporate structures.
- Consumers check whether a contractor, vendor, or service provider is legitimately registered before paying them.
- Compliance teams monitor competitor filings, track foreign registrations, and maintain vendor records.
What an Illinois entity record shows
When you pull up a business in the Illinois Secretary of State Business Search, the record typically includes the entity's legal name and any assumed names, its entity type (LLC, corporation, limited partnership, etc.), current status, formation or registration date, the name and address of the registered agent, and the principal office address. Some states also list the names of officers or members. This is the same information banks, landlords, and courts rely on when verifying a business.
Common Illinois search mistakes
- Searching the exact full name only — try a partial name or drop the "LLC"/"Inc." suffix if you get zero results.
- Assuming a name is available because it isn't an exact match — the state also rejects names that are "deceptively similar" to existing entities.
- Confusing a trade name or DBA with the legal entity name — search both if the business operates under a brand name.
- Not checking the entity status — an "Active" name may belong to a dissolved or revoked entity that still blocks your filing.
Illinois business name rules
Before you file, make sure your chosen name satisfies Illinois's naming rules. The Illinois Secretary of State Business Search will reject your filing if the name fails any of these checks:
- Distinguishable on record. Your name must be distinguishable from every existing Illinois entity name. Use the search tool above to check for exact and similar matches first.
- Required designator. LLC names must include an entity designator such as "LLC", "L.L.C.", or "Limited Liability Company". Corporations must include "Inc.", "Corp.", "Corporation", or an equivalent.
- Restricted words. Words that imply a regulated profession (bank, insurance, attorney, university) or a government affiliation may require extra approvals or be prohibited outright.
- Name reservation available. Name reservation fee is $25 and holds the name for 90 days. Reservation costs $25 and is useful when you found a good name but are not ready to file yet.
How to reserve a business name in Illinois
Name reservation fee is $25 and holds the name for 90 days.
How it works: First confirm the name is available using the search tool at the top of this page. Then file a name reservation application with the Illinois Secretary of State Business Search and pay the fee. The state holds the name for you so no one else can register it while you finish preparing your formation documents. When you are ready, file your Articles of Organization and use the reserved name.
Reservation is optional — if you plan to file right away, you can skip it and just form the LLC. It is most useful when you found a great name but need a few weeks to sort out your operating agreement, EIN, or funding.
Registered agent requirement in Illinois
Every Illinois LLC and corporation must maintain a registered agent — a person or company with a physical street address in Illinois who is available during normal business hours to receive legal documents (service of process) and official state mail on behalf of the business. You can act as your own registered agent if you live in the state, but many owners use a commercial registered agent service so their home address stays off the public record and they never miss a legal delivery. The registered agent's name and address appear in the public entity record, which is one reason privacy-conscious owners hire a service.
When was this data last verified?
This page was last verified on 2026-08-15. Our verification system automatically re-checks filing fees, processing times, office addresses, and portal links every month and monitors each state's official source pages for changes. If you spot anything out of date, the Illinois filing office occasionally updates fees mid-year — the sources below are the authoritative references.
Frequently asked questions about Illinois business entity search
How do I look up a business entity in Illinois?
Visit the Illinois Secretary of State Business Search and search by company name, entity number, or registered agent. Most searches return results immediately and show entity status, formation date, and registered agent.
How much does it cost to form an LLC in Illinois?
The Illinois LLC filing fee is $150. LLC Articles of Organization filing fee is $150.
How long does Illinois entity approval take?
Standard processing is 5-10 business days. Expedited service is available for $50 and completes in 24 hours.
Does Illinois require an annual report?
Yes. Illinois Anniversary of formation with a fee of $75. Late filing can result in no monetary penalty, but the entity risks administrative dissolution.
How do I get a Certificate of Good Standing in Illinois?
Order it through the Illinois Secretary of State Business Search. The certificate confirms your entity is registered, active, and current on its filings. Banks, lenders, and other states typically require it when opening accounts, applying for loans, or registering as a foreign entity.
Can I reserve a business name in Illinois?
Yes. Name reservation costs $25. Name reservation fee is $25 and holds the name for 90 days.
Can I search by registered agent in Illinois?
Yes. The Illinois Secretary of State Business Search supports searches by registered agent name. This is useful for tracking all entities managed by the same agent.
Do I need a registered agent in Illinois?
Yes. Every Illinois LLC and corporation must maintain a registered agent with a physical street address in the state. You can be your own agent or hire a commercial registered agent service.
What is the difference between an LLC and a corporation in Illinois?
An LLC offers flexible, pass-through taxation with minimal paperwork, while a corporation can issue stock and is better suited for raising investor capital. Both limit personal liability. Most small businesses in Illinois choose the LLC.
Is the Illinois business entity search free?
Yes. Searching the official Illinois database is free. You only pay if you order certified copies, certificates of existence, or file documents.
How do I check if a Illinois business is still active?
Search the business name on the Illinois Secretary of State Business Search and look at the entity status field. "Active" or "Good Standing" means the entity is current; "Dissolved", "Revoked", or "Forfeited" means it has lost its standing.
Illinois business entity statistics
Illinois is home to roughly 12.55M residents and recorded 132,900 new business formations in 2023. Chicago is the largest city in the state and the most common location for principal offices.