Illinois LLC Name Search

How to search for LLC names in Illinois

Searching for an available LLC name in Illinois is a required step before submitting your Articles of Organization to the Illinois Secretary of State. The state's online business entity search database lets you look up existing LLC names, corporations, and other registered entities to check for conflicts. Searching the database tells you whether a name is currently in use, but finding no exact match does not guarantee your chosen name will be approved — the Secretary of State also applies a "distinguishable" standard, meaning names that are too similar to existing entities may still be rejected. Running a thorough search before filing saves you the cost and delay of a rejected application. The database is updated regularly and reflects active, inactive, and reserved business names across all entity types registered in Illinois.

Step-by-step: using the Illinois Secretary of State name search

1. 1. Go to the Illinois Secretary of State Business Entity Search at https://www.ilsos.gov/corporatellc/ and select the 'LLC' entity type from the search options.
2. 2. Enter your desired LLC name or a keyword in the name field. You can search by exact name or partial name — searching a distinctive keyword from your name often catches more potential conflicts than an exact-phrase search.
3. 3. Review the results list carefully. Look for any active or inactive entities with the same name or a name that sounds similar, looks similar when typed, or differs only by punctuation, spacing, or common words like 'the' or 'and'.
4. 4. Click individual entity names in the results to view their status. An entity marked 'Active' or 'Reserved' means that name is unavailable. An 'Inactive' or 'Dissolved' entity may still block your name if the Secretary of State deems it not sufficiently distinguishable.
5. 5. If no conflicting names appear, note your exact proposed name — including the LLC designator — and proceed to file your Articles of Organization (Form LLC-5.5) online through the Illinois Secretary of State's business services portal or by mail.

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Illinois LLC naming rules

• Your LLC name must include 'Limited Liability Company', 'L.L.C.', or 'LLC' as the last words of the name — abbreviations with or without periods are both acceptable under Illinois law.
• The name must be distinguishable from all other business entity names already on record with the Illinois Secretary of State, including corporations, LLCs, limited partnerships, and reserved names.
• Your name cannot contain language that implies the LLC is a government agency, such as 'State', 'Federal', 'United States', 'U.S.', or any term that suggests an official government connection.
• Words such as 'Bank', 'Banking', 'Trust', 'Insurance', 'Cooperative', and similar regulated terms require written approval or licensure from the relevant Illinois regulatory authority before the Secretary of State will accept the name.
• Professional designations like 'Attorney', 'Doctor', 'Engineer', 'Architect', or 'CPA' in an LLC name generally require that all members hold the applicable professional license, and some professions must organize as a Professional LLC (PLLC) instead.
• The name cannot contain obscene, profane, or misleading language, and cannot falsely suggest the LLC is organized for a purpose not stated in its Articles of Organization.
• Punctuation differences, plural versus singular forms, or the addition of common articles and prepositions alone are not enough to make a name 'distinguishable' — the Secretary of State looks at the overall impression of the name.
• If your desired name is identical or confusingly similar to an existing entity's name, you may file a written consent from the existing entity and submit it with your Articles of Organization to request an exception.

Restricted words in Illinois LLC names

The following words require special approval from a state agency before you can use them in your Illinois LLC name:

• Bank / Banking / Banker — requires Illinois Department of Financial and Professional Regulation approval
• Trust / Trust Company — requires approval from the Illinois Department of Financial and Professional Regulation
• Insurance / Insurer / Underwriter — requires Illinois Department of Insurance authorization
• University / College — implies accredited educational institution and requires approval
• Attorney / Lawyer — implies licensure; professional LLC structure and bar membership typically required
• Engineer / Engineering — requires licensure through the Illinois Design Professionals licensing board
• Cooperative / Co-op — implies a specific cooperative legal structure governed by Illinois cooperative statutes
• Federal / United States / U.S. — implies government affiliation and is prohibited without authorization

How to reserve an LLC name in Illinois

Illinois allows you to reserve an LLC name before filing your Articles of Organization by submitting Form LLC-1.15 (Application to Reserve a Name) along with a $25 filing fee to the Illinois Secretary of State. A reservation holds the name exclusively for 90 days and is not renewable — if you need more time, you must file a new reservation application with a new fee once the current reservation expires. Reservations can be filed by mail or in person at the Springfield office.

Tips for choosing an LLC name that passes in Illinois

• Search both the exact name you want and common misspellings or phonetically similar versions — the Secretary of State can reject names that sound alike even if they are spelled differently.
• After checking the Illinois business database, run a search on the USPTO federal trademark database at https://www.uspto.gov/trademarks/search to make sure your name does not infringe on a federally registered mark.
• Check domain name availability for your LLC name at the same time as your state search — securing a matching .com or .llc domain early prevents branding conflicts down the road.
• Avoid names that are hyper-local to a single city or neighborhood if you plan to expand operations across Illinois or other states, as geographic descriptors can limit your brand and sometimes conflict with local government entity names.
• Keep the name broad enough to cover future products or services — if your LLC grows beyond its original focus, an overly specific name can create marketing challenges and may require a costly amendment filing.
• Consider reserving your chosen name with a Form LLC-1.15 ($25 fee, 90-day hold) as soon as you confirm availability, especially if your Articles of Organization will take several weeks to prepare or if you are waiting on professional approvals.