Est. April 17, 1998 · A Corp USA company · IL LLC $299 · IL Corp $324 · Annual Report $174(386) 465-3937

Illinois field guide / 02 / Formation decisions

Illinois Series LLC — Forms LLC-5.5(S) & LLC-37.40

01 / The direct answer

Form LLC-5.5(S) & Form LLC-37.40 · 805 ILCS 180/37-40. $599 umbrella + $50 per Certificate of Designation. Under 805 ILCS 180/37-40(b), vertical and horizontal liability segregation requires separate records, assets and statutory notice. Suitable for real estate and multi-location operations.

Illinois General Assembly — 805 ILCS ↗Illinois Secretary of State — Department of Business Services ↗

Illinois statutory references supplied for the October 28, 2026 review; confirm current official instructions.

Corp USA is not a law firm and does not provide legal advice. Private information and filing service; not a government agency.

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Corp USA is not a law firm and does not provide legal advice.

02 / Follow the decisions

Start with the right question.

Filing and legal basis

Form LLC-5.5(S) & Form LLC-37.40 · 805 ILCS 180/37-40. $599 umbrella + $50 per Certificate of Designation. Under 805 ILCS 180/37-40(b), vertical and horizontal liability segregation requires separate records, assets and statutory notice. Suitable for real estate and multi-location operations.

Illinois General Assembly — 805 ILCS ↗

Annual Illinois compliance

Illinois Annual Reports (Form LLC-50.1 under 805 ILCS 180/50-1; Form BCA 14.05 under 805 ILCS 5/14.05) are due before the first day of the anniversary month: the last day of the previous month. The window opens 60 days before that first day. $75 state + $99 service = $174; nonprofits use Form NFP 114.05 ($10 + $99 = $109). Series LLCs add $50 per active registered series. LLCs incur a $100 late penalty after 60 days; 180 days without filing triggers an administrative-dissolution warning. Reinstatement uses Form LLC-35.40 or BCA 12.45: $200 state + $299 service plus back reports and penalties.

Illinois Secretary of State — Department of Business Services ↗

Statewide vs. local requirements

LLC formation requires no newspaper publication. Statewide LLC/corporation assumed names use Form LLC-1.20 / BCA 4.15 with zero newspaper publication. Sole proprietors and general partnerships register with the County Clerk under 805 ILCS 405/1 and publish once each week for three consecutive weeks; confirm filing, publication and proof deadlines with the clerk.

Illinois General Assembly — 805 ILCS ↗
03 / Before you proceed

Your preparation checklist

  • Confirm entity type and Illinois eligibility
  • Check ILSOS entity name and existing status
  • Confirm the filing form, state fee and service quote
  • Maintain an Illinois registered agent and physical registered office
  • Retain stamped filings and governing records
  • Calendar the anniversary-month report and applicable IDOR/IRS filings
  • File LLC-5.5(S) and each LLC-37.40 designation
  • Maintain separate records and assets for every series
Illinois General Assembly — 805 ILCS ↗Illinois Secretary of State — Department of Business Services ↗
04 / Your decision tool

Illinois Series LLC — Forms LLC-5.5(S) & LLC-37.40

Illinois Series LLC — Forms LLC-5.5(S) & LLC-37.40

Illinois Startup, Series LLC & 24-Hour Filing Costs

State formation fee

$150

Designations / IDFPR / expedited

$0

Corp USA service

$149

Startup total

$299

Year 2 report forecast: $75 state + $99 service = $174. Corporation franchise tax is $0 when liability does not exceed the $1,000,000 exemption. Series LLC $599 is the umbrella price before designations.

805 ILCS 180/37-40, 50-10; 805 ILCS 5/15.35. No newspaper publication for LLC formation. Shipping and applicable tax are separate.

Start Illinois filing — $299
Review the filing & fees →
05 / Facts & fees

Keep the requirements separate.

Illinois statutory references; confirm current requirements before filing.
RequirementRule / confirmation neededOfficial authority
Filing and legal basisForm LLC-5.5(S) & Form LLC-37.40 · 805 ILCS 180/37-40. $599 umbrella + $50 per Certificate of Designation. Under 805 ILCS 180/37-40(b), vertical and horizontal liability segregation requires separate records, assets and statutory notice. Suitable for real estate and multi-location operations.Illinois General Assembly — 805 ILCS ↗
Annual Illinois complianceIllinois Annual Reports (Form LLC-50.1 under 805 ILCS 180/50-1; Form BCA 14.05 under 805 ILCS 5/14.05) are due before the first day of the anniversary month: the last day of the previous month. The window opens 60 days before that first day. $75 state + $99 service = $174; nonprofits use Form NFP 114.05 ($10 + $99 = $109). Series LLCs add $50 per active registered series. LLCs incur a $100 late penalty after 60 days; 180 days without filing triggers an administrative-dissolution warning. Reinstatement uses Form LLC-35.40 or BCA 12.45: $200 state + $299 service plus back reports and penalties.Illinois Secretary of State — Department of Business Services ↗
Statewide vs. local requirementsLLC formation requires no newspaper publication. Statewide LLC/corporation assumed names use Form LLC-1.20 / BCA 4.15 with zero newspaper publication. Sole proprietors and general partnerships register with the County Clerk under 805 ILCS 405/1 and publish once each week for three consecutive weeks; confirm filing, publication and proof deadlines with the clerk.Illinois General Assembly — 805 ILCS ↗
06 / Your next path

Carry the decision forward.

Continue with our filing team

Corp USA is not a law firm and does not provide legal advice. State fees are pass-through. Service fees and taxes are separate. Review the order price before payment.

07 / Questions answered

Before your next step

Form LLC-5.5(S) & Form LLC-37.40 · 805 ILCS 180/37-40. $599 umbrella + $50 per Certificate of Designation. Under 805 ILCS 180/37-40(b), vertical and horizontal liability segregation requires separate records, assets and statutory notice. Suitable for real estate and multi-location operations.

Illinois General Assembly — 805 ILCS ↗

Illinois Annual Reports (Form LLC-50.1 under 805 ILCS 180/50-1; Form BCA 14.05 under 805 ILCS 5/14.05) are due before the first day of the anniversary month: the last day of the previous month. The window opens 60 days before that first day. $75 state + $99 service = $174; nonprofits use Form NFP 114.05 ($10 + $99 = $109). Series LLCs add $50 per active registered series. LLCs incur a $100 late penalty after 60 days; 180 days without filing triggers an administrative-dissolution warning. Reinstatement uses Form LLC-35.40 or BCA 12.45: $200 state + $299 service plus back reports and penalties.

Illinois Secretary of State — Department of Business Services ↗