Illinois lesson 1 of 6
Name your Illinois LLC
The Illinois Secretary of State will reject Form LLC-5.5 if the proposed name is not distinguishable from a name already on file, so checking first avoids losing time and the $150 fee to a rejected filing.
Required wording
An Illinois LLC name must contain the words Limited Liability Company or the abbreviation L.L.C. or LLC. Limited and Company may be abbreviated to Ltd. and Co.
- Acceptable: Prairie Grain Traders LLC, Prairie Grain Traders L.L.C.
- Not acceptable: wording implying a corporation, bank, or government agency without approval
- Some words need consent from the state agency that regulates that industry
Checking the name is free
Search the Secretary of State's business entity database before filing. Illinois applies a distinguishable name requirement, so close variations of an existing name, differing only in punctuation or a designator, are usually refused.
A trading name that differs from the LLC's registered name is filed as an assumed name with the Secretary of State, separate from the Articles of Organization.
🇺🇸 Check United States company name availability
Search the official United States state registry before you file. Opens the government portal in a new tab.
Tip: also confirm the .com domain and matching social handles are free before you commit.
Key takeaways
- End the name with LLC, L.L.C. or Limited Liability Company.
- Illinois requires a distinguishable name, not just an exact match.
- Search the Secretary of State register before filing Form LLC-5.5.
Official sources
Or let us file your Illinois LLC for you
Everything above is yours to use for free. If you would rather hand it over, we prepare and file the Articles of Organization (Form LLC-5.5), act as your registered agent, and track your ongoing deadlines.
Last reviewed: September 2026 - reviewed by Gullia Filing Legal & Formation Team