Short answer. Individuals and partnerships file an assumed name certificate with the county clerk where the business is located (Assumed Business Name Act, 805 ILCS 405). LLCs and corporations file an application with the Secretary of State. The county pages we read don't say how long an individual's certificate lasts.
At a glance
- Called
- assumed business name (assumed name for LLCs and corporations)
- Where to file
- Depends on the owner
- Filing fee
- Secretary of State, for an LLC or corporation: $150 in a year ending in 0 or 5, then $120, $90, $60 and $30 in years ending in 1/6, 2/7, 3/8 and 4/9; renewal is $150. The county clerk sets its own fee ($19 in Stephenson County).
- How long it lasts
- Individuals: see the rule; entities: up to 5 years
- Newspaper notice
- Yes, county filings
Individuals and companies file in different places
Individuals and partnerships file an assumed name certificate with the county clerk where the business is located (Assumed Business Name Act, 805 ILCS 405). LLCs and corporations file an application with the Secretary of State.
Renewal, with dates
The county pages we read don't say how long an individual's certificate lasts. For an LLC or corporation: runs until the first day of its anniversary month in the next year divisible by 5 (filed in the two months before that month in such a year, it runs to the following one). Renew within the 60 days before, for five years, on the annual report.
For a registration filed on Tuesday, November 17, 2026:
- Sole proprietor or partnership: The county pages we read don't say how long an individual's certificate lasts.
- LLC or corporation: runs until Friday, March 1, 2030; renewal window opens Monday, December 31, 2029 (for a company formed in March)
The newspaper notice
County filings: publish once a week for three consecutive weeks, the first within 15 days of filing, and get the certificate of publication to the county clerk within 50 days of filing or the registration is void.
Filed on Tuesday, November 17, 2026, the dates work out as:
- First notice by: Wednesday, December 2, 2026
- Last of the 3 weekly notices, if the first runs that day: Wednesday, December 16, 2026
- Proof of publication filed by: Wednesday, January 6, 2027
Your own date: open the calculator set to Illinois.
Not stated on the pages we read: whether local fees differ and online filing.
Official sources
- Stephenson County Clerk: Registration of assumed names (DBAs) (checked November 2026)
- 805 ILCS 180/1-20: LLC assumed names (checked November 2026)
- 805 ILCS 180/50-10: LLC fees (checked November 2026)
- 805 ILCS 5/4.15: Corporate assumed names (checked November 2026)
- 805 ILCS 5/15.10: Corporate fees (checked November 2026)
General information, not legal advice; we are not lawyers. Checked November 2026 against the pages above. Fees and forms change, and a county or town office can add its own steps, so confirm with the filing office before you file. We don't file DBAs or trade names for anyone.
Questions people ask
Where is a DBA filed in Illinois?
It's called a assumed business name (assumed name for LLCs and corporations). Individuals and partnerships file an assumed name certificate with the county clerk where the business is located (Assumed Business Name Act, 805 ILCS 405). LLCs and corporations file an application with the Secretary of State.
What does it cost to register a business name in Illinois?
Secretary of State, for an LLC or corporation: $150 in a year ending in 0 or 5, then $120, $90, $60 and $30 in years ending in 1/6, 2/7, 3/8 and 4/9; renewal is $150. The county clerk sets its own fee ($19 in Stephenson County).
How long does a Illinois assumed business name last?
The county pages we read don't say how long an individual's certificate lasts. For an LLC or corporation: runs until the first day of its anniversary month in the next year divisible by 5 (filed in the two months before that month in such a year, it runs to the following one). Renew within the 60 days before, for five years, on the annual report.
Does Illinois require a newspaper notice?
Yes. County filings: publish once a week for three consecutive weeks, the first within 15 days of filing, and get the certificate of publication to the county clerk within 50 days of filing or the registration is void.
All states: DBA registration by state · Georgia · Minnesota