Illinois LLC Formation 2026: Costs, Deadlines, and the Chicago Tax Reality

Quick-Read

- **Formation filing fee**: $150 (online) or $150 + $100 expedite - **Annual report fee**: $75 due within 60 days after first day of anniversary month - **Miss the deadline**: $100 late fee, then involuntary dissolution at 6+ months - **Chicago specific**: 9.5% personal property lease transaction tax on certain B2B leases - **Illinois income tax**: 4.95% flat rate on pass-through income

Step 1: Choose a Name

Your Illinois LLC name must include "LLC," "L.L.C.," or "Limited Liability Company" and must be distinguishable from existing business entities on the Illinois Secretary of State business database. Search at apps.ilsos.gov.

Name reservation (optional): $25 for 90 days if you want to lock in the name before filing Articles of Organization.

Step 2: Appoint a Registered Agent

Every Illinois LLC needs a registered agent with a physical Illinois street address (no PO boxes). You can: - Be your own agent if you have an IL address (privacy trade-off: your address is public record) - Hire a professional service ($50-$299/year) - FormifyAI includes registered agent service with every plan

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

File online at ilsos.gov/businessservices ($150) or by mail ($150). Required info:

- LLC name - Purpose (boilerplate "any lawful purpose" works) - Name and address of registered agent - Duration (perpetual or specific end date) - Management structure (member-managed vs manager-managed) - Signature of organizer

Standard processing: 10 business days online, 3-4 weeks by mail. Expedited (24 hours) adds $100.

Step 4: Draft an Operating Agreement

Illinois doesn't legally require an operating agreement, but you need one anyway. Banks require it for business account opening. Courts look at it during veil-piercing lawsuits. See our [operating agreement guide](/blog/operating-agreement-common-mistakes) for what to include.

Step 5: Obtain an EIN

Free at irs.gov/ein. Required to open a business bank account and hire employees. Takes 15 minutes online during business hours.

Step 6: Register with Illinois Department of Revenue

If you'll have employees or sell taxable goods in Illinois, register at mytax.illinois.gov for:

- **Withholding tax account** (if hiring employees) - **Sales tax permit** (if selling taxable goods/services) - **Unemployment insurance** (if hiring employees)

Registration is free. You'll get an Illinois Business Tax Number.

Step 7: File Annual Report Every Year

Due within 60 days after the first day of your LLC's anniversary month (the month your Articles were filed). Fee: $75.

Miss the deadline: $100 late fee. Stay delinquent for 6 months: the Illinois Secretary of State administratively dissolves your LLC, which means you lose liability protection until you pay back fees + reinstatement.

The Chicago Tax Reality

Most Illinois LLCs pay just state taxes. LLCs operating in Chicago face additional local taxes:

**Chicago Personal Property Lease Transaction Tax**: 9.5% on equipment leases and certain software/SaaS purchases. If your LLC leases office equipment or subscribes to certain cloud services, you may owe this tax monthly.

**Chicago Use Tax**: 1.25% on personal property purchased outside Chicago for use in Chicago.

**Restaurant tax**: additional 0.25% on food/drink if your LLC operates restaurants.

**Ground Transportation tax**: affects Uber/Lyft-type driver LLCs.

These are on top of Illinois's 6.25% sales tax + Chicago's 3.75% home rule sales tax. Combined sales tax in Chicago hits 10.25% for most goods.

Illinois Pass-Through Income Tax

Your Illinois LLC's profit passes through to your personal Illinois return. Illinois imposes:

- **Individual income tax**: 4.95% flat rate (no brackets) - **Personal Property Replacement Tax (PPRT)**: 1.5% for partnerships; S-Corps pay 1.5% at entity level

Total effective state tax on LLC income if single-member: 4.95%. Total for multi-member LLC taxed as partnership: 4.95% + 1.5% PPRT = 6.45%.

Transitioning to S-Corp

Once your Illinois LLC clears ~$60-80K profit, S-Corp election often makes sense to reduce self-employment tax. Note Illinois quirks:

- Illinois recognizes federal S-Corp election automatically (no separate state election) - S-Corps owe 1.5% PPRT at entity level - Reasonable salary still applies (Illinois follows federal rules)

Use our [S-Corp Savings Calculator](/tools/s-corp-savings) to see break-even for your profit level.

Common Mistakes

1. **Filing annual report late**: the $100 late fee hurts, but admin dissolution is worse — you lose liability protection retroactively for the period you were dissolved.

2. **Not registering for Illinois tax accounts before hiring**: employers without a withholding account get back-tax penalties for every unregistered payday. Register BEFORE your first employee's first check.

3. **Missing Chicago-specific taxes**: if your LLC is Chicago-based, factor in 9.5% personal property lease tax on anything you lease, plus the 10.25% combined sales tax.

What to Do Next

If you're forming an Illinois LLC, [FormifyAI's Illinois formation package](/form-llc/illinois) handles Articles of Organization + registered agent + EIN + operating agreement + annual report reminders. $39/mo annual. If you already have an IL LLC, make sure your annual report reminder is calendared — the $100 late fee is preventable.