How to Start an LLC in Illinois: Cost, Steps, and Requirements

Illinois made itself much cheaper to enter a few years ago by slashing its LLC formation fee from $500 to $150 — but it remains one of the more expensive states to operate an LLC in, thanks to two things most guides gloss over: an anniversary-month deadline that’s easy to miss by a month, and a Personal Property Replacement Tax that hits the entity directly. This guide covers the cost, the timeline, the annual requirements, the seven filing steps, both Illinois-specific catches, how a Illinois LLC is taxed, and how Illinois compares to sole proprietorships, Delaware, and Florida.

Everything below is verified against the Illinois Secretary of State and Department of Revenue, but fees and rates change. This is educational, not legal or tax advice — confirm current figures with the Secretary of State before you file, and talk to a CPA or attorney about your specific situation. It’s part of our broader guide to LLC vs S-corp vs sole proprietorship.

How do you start an LLC in Illinois?

Starting an LLC in Illinois means choosing a compliant name, appointing a registered agent with an Illinois street address, filing the Articles of Organization (Form LLC-5.5) with the Illinois Secretary of State, Department of Business Services, and paying the $150 filing fee. Most online filings are processed within about a week to ten business days.

Illinois’s process is handled through the Secretary of State’s online business services at ilsos.gov. From there, the sequence is: name → registered agent → Articles of Organization → operating agreement → EIN → state tax registration → business bank account. Illinois has no newspaper publication requirement (unlike Arizona), which removes one source of cost and confusion. Two things are worth internalizing up front, because they’re where Illinois differs from most states: the annual report deadline is keyed to your anniversary month in a slightly counterintuitive way, and the state imposes an entity-level Replacement Tax on top of your personal income tax. Both are covered in detail below.

How much does it cost to start an LLC in Illinois?

Starting an LLC in Illinois costs $150 to file the Articles of Organization (Form LLC-5.5) with the Secretary of State, or $400 for a Series LLC (Form LLC-5.25). After that, the main recurring cost is the $75 Annual Report each year. Illinois has no separate franchise tax on LLCs and no publication requirement, which keeps the headline cost moderate.

Here’s the full first-year cost picture, with figures from the Illinois Secretary of State’s LLC fee schedule:

If you need speed, Illinois offers expedited ~24-hour processing for an additional $100. Other common fees: registering an out-of-state LLC as a foreign LLC in Illinois is $150 (same as domestic), changing your registered agent is $25, and reinstating an administratively dissolved LLC is $200 plus outstanding fees. Note that Illinois cut its formation fee from $500 to $150 a few years ago, so any source still quoting $500 is badly out of date — verify current fees on the Secretary of State’s schedule before filing.

How long does it take to form an LLC in Illinois?

Illinois LLC processing times vary, but online filings are typically processed in roughly 5 to 10 business days, while mail filings take about 10 to 15 business days. If you need it faster, expedited processing for an extra $100 drops the turnaround to about one business day (24 hours).

Because the queue fluctuates, treat any published timeline (including this one) as indicative, and check the Secretary of State’s current turnaround before filing if timing matters. Two practical takeaways: file online rather than by mail, since it’s faster and gives you immediate confirmation, and if you have a hard deadline — a bank appointment, a lease, a closing — pay the $100 expedite rather than gambling on the standard queue. Note that expedited service in Illinois has historically had to be requested in person at the Springfield or Chicago office for some filing types, so confirm the current expedite process with the Secretary of State.

What are the annual requirements for an Illinois LLC?

Every Illinois LLC must file an Annual Report with the Secretary of State each year for $75, due before the first day of the LLC’s anniversary month. This report keeps your registered agent, address, and management information current with the state. Your first Annual Report is due the year after you form — Illinois doesn’t require one in your formation year.

The deadline mechanics trip people up, so read this carefully. The report is due before the first day of your anniversary month, which in practice means the last day of the month before. An LLC approved in June has an anniversary month of June, so its report is due by May 31 each year — not June 30, and not on the June anniversary date. You can file up to 45 days early, and the state mails a courtesy reminder to your registered agent about 45 days out, but the responsibility to file is yours regardless. Miss it and Illinois adds a $100 late penalty (reduced from $300 by House Bill 4578) on top of the $75 fee; keep ignoring it and the state administratively dissolves the LLC, at which point you lose liability protection until you reinstate for $200 plus back fees. Beyond the Annual Report, you must keep a registered agent at all times and file state tax returns — including the Replacement Tax covered below.

How to start an LLC in Illinois in 7 steps

You can start an LLC in Illinois in seven steps: choose a name, appoint a registered agent, file the Articles of Organization, create an operating agreement, get an EIN, register for state taxes and licenses, and open a business bank account. Here’s each step — what it is, why it matters, how to do it, and the mistake to avoid.

Step 1: Choose an Illinois LLC name

Your LLC name must include “Limited Liability Company,” “LLC,” or “L.L.C.” and be distinguishable from every other entity registered with the Illinois Secretary of State. Search the Secretary of State’s business database before you commit to branding, a domain, or signage. You can optionally reserve a name for 90 days for $25 if you’re not ready to file. The mistake is printing materials or buying a domain before confirming the name clears — a rejected name means refiling and a fresh trip through the queue.

Step 2: Appoint a registered agent

A registered agent is the person or company that receives legal documents and state notices for your LLC, and Illinois requires one with a physical Illinois street address (no PO boxes) available during business hours. The agent can be an Illinois resident 18 or older, or a business entity authorized in the state. You can be your own agent, or hire a service (~$100–$300/year) to keep your home address off the public record. The mistake most owners regret is listing their home address as their own agent — it becomes public record, so process servers and marketers can find it. If privacy matters, use a commercial agent.

Step 3: File the Articles of Organization (Form LLC-5.5)

The Articles of Organization is the filing that legally creates your LLC. File Form LLC-5.5 through the Secretary of State and pay $150 (a Series LLC uses Form LLC-5.25 and costs $400). You’ll provide the LLC name, principal place of business, registered agent and address, purpose, and management structure. The mistake is filing the wrong form — a standard LLC uses LLC-5.5; only choose the $400 Series LLC (LLC-5.25) if you specifically need multiple protected “series” under one master LLC, which is a niche structure most small businesses don’t need.

Step 4: Create an operating agreement

An operating agreement is the internal contract that sets ownership percentages, voting rights, profit distributions, management duties, and what happens when a member leaves or the company dissolves. Illinois does not require you to file one with the state, but it is strongly recommended: without it, Illinois’s statutory default rules govern your company, and those defaults may not match what you and your co-owners intended. Even single-member LLCs benefit — it evidences the separation between you and the business that liability protection rests on. See our guide to LLC vs S-corp vs sole proprietorship for how ownership and tax elections interact. The mistake is skipping it because “it’s just me.”

Step 5: Get an EIN from the IRS

An EIN (Employer Identification Number) is your business’s federal tax ID, and it’s free from the IRS online in about ten minutes. You need it to open a business bank account, register with the Illinois Department of Revenue, hire employees, and handle most tax filings — and a multi-member LLC needs one by default. Get your EIN directly from the IRS — never pay a third-party site for what the government gives away for nothing. The mistake is paying a service $50–$100 for a free ten-minute form.

Step 6: Register for Illinois state taxes and licenses

If your LLC sells taxable goods or has employees, register with the Illinois Department of Revenue (via MyTax Illinois) for sales tax and withholding. Critically, Illinois LLCs taxed as partnerships or S-corps must also file and pay the Personal Property Replacement Tax (Form IL-1065 for partnerships) — 1.5% of net income — which is separate from your personal income tax. Illinois has no statewide general business license, but many cities (Chicago especially) require local licenses, so check locally. See our guide to small business taxes. The mistake is overlooking the Replacement Tax, which many owners don’t learn about until their first tax season.

Step 7: Open a business bank account and stay compliant

Open a dedicated business bank account as soon as your EIN arrives, and run every dollar of business income and expense through it. This isn’t just bookkeeping hygiene — it’s what preserves your liability protection. Commingling personal and business funds is the most common way owners hand a plaintiff the argument that the LLC is a sham and the “corporate veil” should be pierced. Then calendar your real obligations: the $75 Annual Report before your anniversary month, the Replacement Tax return, sales-tax returns if applicable, and any local license renewal. Consider coverage too — see our guide to business insurance types and costs. The mistake is treating the LLC as a formality while running money through a personal account.

The anniversary-month deadline and the Replacement Tax

Two Illinois-specific rules cost owners real money if they’re missed, and neither gets enough attention in generic guides.

First, the anniversary-month deadline. Your $75 Annual Report is due before the first day of your LLC’s anniversary month — which is a slightly awkward way of saying the last day of the preceding month. If your LLC was approved in June, your anniversary month is June, and your report is due by May 31, not June 30 and not on your June formation date. Owners who assume the deadline is “sometime in my anniversary month” or “on my anniversary date” routinely file a few days late and get hit with the $100 penalty, which applies if you file more than 60 days after the due date (the penalty was reduced from $300 by House Bill 4578). The fix is simple: set a recurring calendar reminder for about 45 days before the first of your anniversary month, since Illinois lets you file up to 45 days early.

Second, the Personal Property Replacement Tax (PPRT). This is the cost most state guides omit entirely. Per the Illinois Department of Revenue, Illinois levies a Replacement Tax on the net income of the business entity itself — 1.5% for LLCs taxed as partnerships or S-corporations (and 2.5% for those taxed as C-corporations). This is a genuine entity-level tax that sits on top of the members’ 4.95% personal income tax on the same profits. So an Illinois LLC taxed as a partnership effectively faces the 1.5% Replacement Tax at the entity level plus 4.95% at the member level on its Illinois net income. It’s not enormous, but it’s real money that owners coming from states without an equivalent tax don’t expect, and it’s why Illinois is cheaper to form than to run. (Educational, not tax advice — confirm current rates and filing obligations with the Illinois Department of Revenue.)

How is an Illinois LLC taxed?

An Illinois LLC is a pass-through entity by default: the LLC itself pays no federal income tax, and profits flow to the members’ personal returns (a single-member LLC is a “disregarded entity”; a multi-member LLC is taxed as a partnership). At the state level, that pass-through income is taxed on the member’s Illinois return at the state’s flat 4.95% individual income tax rate. On top of that, the LLC owes the 1.5% Personal Property Replacement Tax on its net income at the entity level.

Three more things shape an Illinois LLC’s tax picture. First, self-employment tax (15.3%) still applies to active members’ earnings — the LLC structure doesn’t avoid it, which is why profitable LLCs sometimes elect S-corp taxation to reduce it (worth discussing with a CPA). Second, a useful planning note: Illinois does not recognize the federal Qualified Business Income (QBI) deduction under Section 199A, so the 20% federal QBI break doesn’t reduce your Illinois taxable income — a detail that surprises owners who assume federal and state treatment match. Third, Illinois offers an elective pass-through entity (PTE) tax at 4.95%, which some partnerships and S-corps use to work around the federal $10,000 SALT deduction cap; whether it helps depends on your situation, so ask a CPA. See our guide to small business taxes. (Educational, not tax advice — confirm current rates with the Illinois Department of Revenue and the IRS.)

LLC vs sole proprietorship in Illinois

An LLC and a sole proprietorship differ most in one respect that outweighs the rest: an LLC creates a legal separation between you and your business, and a sole proprietorship does not. In Illinois, that protection costs $150 to form and $75 a year to maintain (plus the Replacement Tax on business net income). The table compares them.

One Illinois-specific wrinkle worth noting: because a sole proprietorship is not subject to the Personal Property Replacement Tax while a partnership-taxed LLC is, the LLC carries a slightly higher ongoing tax cost. That doesn’t change the core calculus — if your business has any real liability exposure (contracts, a physical product, employees, clients on your premises, debt), the LLC’s protection is almost always worth $150 up front and the modest ongoing cost. A sole proprietorship makes sense only for a true hobby or minimal-risk side income you’re testing.

Illinois LLC vs forming in Delaware, Wyoming, or Nevada

If you live and do business in Illinois, forming your LLC in Delaware, Wyoming, or Nevada is usually a costly mistake. The reason is the foreign-registration trap: an out-of-state LLC that actually operates in Illinois must register in Illinois as a foreign LLC anyway — $150, the same as forming domestically — while still paying the other state’s fees and maintaining a registered agent in both states. You’d also still owe Illinois tax (including the Replacement Tax) on Illinois-source income. You end up with two filings, two agents, and two sets of compliance for no real benefit. The table compares them.

The Delaware advantage is real, but it’s for venture-backed startups raising institutional money, which expect Delaware’s corporate law and Court of Chancery. It is not for a local contractor, consultant, or e-commerce seller operating from Chicago or Springfield. Forming in Wyoming or Nevada to chase “no state income tax” doesn’t help either, because Illinois still taxes income you earn in Illinois. Form where you do business — for an Illinois business, that’s Illinois.

Do you need a registered agent for an Illinois LLC?

Yes. Every Illinois LLC must appoint and continuously maintain a registered agent with a physical Illinois street address (no PO boxes) available during business hours to receive legal documents and state notices. The agent can be an Illinois resident 18 or older, or an authorized business entity. You can serve as your own agent, or hire a commercial service (~$100–$300/year) to keep your home address off the public record.

Can a non-resident form an LLC in Illinois?

Yes. Illinois has no residency or citizenship requirement to form an LLC — out-of-state residents and non-U.S. citizens can both do it. What you must have is a registered agent with a physical Illinois street address. Non-U.S. owners can obtain an EIN without a Social Security number by filing Form SS-4 with the IRS, and should get professional advice on any additional federal reporting obligations.

Is an LLC worth it in Illinois?

Usually yes. Illinois cut its formation fee from $500 to $150, making it affordable to start, and the $75 annual report is modest. The one thing that makes Illinois pricier to run than some neighboring states is the 1.5% Personal Property Replacement Tax on business net income. For most businesses with real liability exposure, the protection still outweighs the cost — just budget for the Replacement Tax and the anniversary-month deadline.

LLC formation services for Illinois

There are three honest paths to forming an Illinois LLC, and none of the mentions here are sponsored — this section is purely editorial:

• DIY, directly with the Secretary of State (cheapest — always): file the Articles of Organization yourself through the Illinois SOS website for the $150 state fee. Nothing is cheaper, and nothing you can buy makes the filing itself any more valid. For most single-member LLCs, this is genuinely a 30-minute task.
• Registered-agent service (~$100–$300/year): worth paying for if you want your home address off the public record, or you don’t have a reliable Illinois street address available during business hours.
• Full formation service: these companies file the same $150 form on your behalf and add their fee on top. They can save time and often bundle a registered agent, but understand you’re paying for convenience, not a better outcome. Watch for services that advertise a low base price and then charge extra for essentials like the EIN or operating agreement (both of which you can get free yourself), and watch for auto-renewing charges.

The honest bottom line: filing directly with the state is always the cheapest path, and Illinois’s online filing is built for ordinary people to use. Pay for a registered agent if privacy matters to you. See our broader how to start a business step-by-step guide for what comes after formation.

Illinois LLC vs Florida LLC: a cost comparison

Illinois and Florida trade off in opposite directions: Florida is cheaper to form and has no state income tax, while Illinois taxes LLC income at 4.95% plus the 1.5% Replacement Tax. For a profitable business, the tax difference dwarfs the modest gap in filing fees. The table compares them.

Over a decade, Illinois’s state filing costs total roughly $825 versus about $1,512 in Florida — so on paperwork alone Illinois is cheaper. But that flips fast once you account for income tax: a Florida member pays no state income tax on profits, while an Illinois LLC pays 4.95% at the member level plus 1.5% Replacement Tax at the entity level. For a business earning $100,000 of taxable profit, that’s roughly $5,000+ a year in Illinois state income tax plus about $1,500 in Replacement Tax that a Florida LLC member wouldn’t pay — which quickly outweighs the filing-fee difference. That said, the decisive factor for almost everyone is simpler: form in the state where you live and operate. Registering in the “cheaper” state while operating in the other just means foreign-registering and paying both. See our guide to starting an LLC in Florida for that side.

Frequently Asked Questions About Starting an LLC in Illinois

Here are quick, standalone answers to the most common questions about forming an Illinois LLC. All are educational, not legal or tax advice.

How much does an LLC cost in Illinois?

An Illinois LLC costs $150 to file the Articles of Organization (Form LLC-5.5) with the Secretary of State, or $400 for a Series LLC (Form LLC-5.25). After formation, you file a $75 Annual Report each year. Optional costs include name reservation ($25), a commercial registered agent (~$100–$300/year), and $100 for expedited ~24-hour processing. Illinois cut this fee from $500, so ignore older sources.

Does Illinois require an LLC annual report?

Yes. Every Illinois LLC must file an Annual Report for $75, due before the first day of the LLC’s anniversary month — effectively the last day of the prior month. An LLC formed in June files by May 31. The first report is due the year after formation. Filing more than 60 days late adds a $100 penalty (reduced from $300 by House Bill 4578), then administrative dissolution.

How long does it take to get an LLC in Illinois?

Illinois LLC processing times vary, but online filings are typically processed in about 5 to 10 business days, while mail filings take roughly 10 to 15 business days. If you need it faster, expedited processing for an extra $100 drops the turnaround to about one business day (24 hours). Filing online is faster and gives you immediate confirmation compared to mail.

Can I be my own registered agent in Illinois?

Yes. You can serve as your own registered agent in Illinois if you have a physical Illinois street address (not a PO box) where you’re available during business hours to accept legal documents. The trade-off is that the address becomes public record. Many owners hire a commercial service (~$100–$300/year) for privacy and to avoid missing important legal or state notices.

Do you need an operating agreement in Illinois?

No, Illinois does not require an operating agreement or require you to file one with the state — but it is strongly recommended. Without one, Illinois’s statutory default rules govern ownership, voting, and distributions, which may not match what you intended. Even single-member LLCs benefit, since the agreement evidences the separation between owner and company that liability protection depends on.