How to search
Illinois LLC names

The Illinois naming rules

Every state writes its own LLC naming rules. Illinois's rules cover three areas: what words you have to include, what words you can't use, and how distinct your name has to be from every other Illinois entity on file.

What you have to include

• The name must end in one of: "LLC," "L.L.C.," or "Limited Liability Company." Illinois accepts variations in spacing and punctuation but the statutory ending is required.
• The name must be in letters, numerals, or standard punctuation the Illinois Secretary of State's filing system accepts. Emoji, non-standard symbols, and most diacritics are rejected.

What you can't use

• Words implying a different entity type: "Corporation," "Corp.," "Incorporated," or "Inc." are not permitted in LLC names.
• Restricted professional terms ("bank," "trust," "insurance," "engineering," "architecture" and similar) usually require licensure and preapproval from the relevant Illinois regulatory body.
• Names that could be confused with a government agency — federal, Illinois state, or municipal.

Distinguishability

Illinois will reject a name that is the same as — or confusingly similar to — an existing Illinois LLC, corporation, partnership, or reserved name. "Confusingly similar" is a judgment call made by the Illinois Secretary of State, not an algorithm; small differences like "Acme Holdings LLC" vs. "Acme Holding LLC" can be rejected.

How to search the Illinois database

1. I.

   Go to the Illinois Secretary of State search tool

   The Illinois business entity search lives at ilsos.gov. Look for "Business Entity Search" or "Name Availability Search" in the main navigation.

2. II.

   Search with multiple variants

   Don't just search the full name — try the distinctive keyword alone, the keyword with and without the "LLC" ending, and the plural/singular forms. A name that passes a "begins with" search can still collide on a "contains" search.

3. III.

   Check for trademark collisions

   The Illinois database only tracks state entity names — it does not check federal trademarks. For a business you plan to brand nationally, also run a USPTO TESS search before committing.

4. IV.

   Confirm the domain

   If the exact match .com is taken by a competitor, treat that as a warning flag — not about state availability, but about everyday confusion in the market.

Should you reserve the name?

Illinois allows name reservation for a fee, typically held for 60 to 120 days. If you're ready to file within a week or two, there's no reason to reserve — just file the Articles directly and the name locks when the LLC is approved. Reservation makes sense if you've picked a name, need to secure it, but aren't ready to file (for example, because you're still finalizing the operating agreement or capital structure).

When you reserve with us, we file the Illinois name-reservation form and hand you the confirmation. Reservation fees are a pass-through Illinois state cost; our service fee is still $299 whether or not you reserve.

What we check before filing

A formation specialist runs the Illinois database before submitting your Articles. If your first choice is taken or likely to be rejected for similarity, we call before filing — we do not submit a filing that isn't going to clear. You tell us your preferred name plus two alternates on the reservation form and we work through them in order.

What's included in the $299 flat fee