Illinois has two DBA systems. Sole proprietors and partnerships file an assumed name certificate with the county clerk under the Assumed Business Name Act, then publish a notice in a local newspaper once a week for 3 weeks. LLCs file an application for an assumed name with the Secretary of State under 805 ILCS 180/1-20, which costs $150 in a year ending in 0 or 5, less in other years, and renews every 5 years, as of October 2026.
Which route you take in Illinois comes down to one thing: whether there's a registered company behind the name. Individuals deal with their county clerk and a newspaper. LLCs deal with the Secretary of State and a fee that shrinks as the five-year cycle runs down.
Sole proprietors and partnerships: the county clerk route
Section 1 of the Assumed Business Name Act, 805 ILCS 405/1, says no person shall conduct business in Illinois under an assumed name, or any name other than the real name of the people running it, unless they file a certificate in the office of the county clerk of the county where they do business. The certificate sets out:
- the name the business will trade under
- the full real name of every person who owns or runs it
- their post office addresses
- every address in the county where the business is, or will be, conducted
The certificate has to be signed and acknowledged by each person, which usually means a notary.
The newspaper notice most people forget
This is the step that sets Illinois apart. After filing, notice must be published in a newspaper of general circulation in that county once a week for 3 consecutive weeks. The first notice has to appear within 15 days after you file, and proof of publication must be filed with the county clerk within 50 days of filing the certificate.
Once the clerk has the proof, they issue a receipt, and the Act says there's no extra charge for that receipt. The Act says that unless proof of publication is made to the clerk, the certificate is void, so don't treat the newspaper step as optional. County clerks set their own filing fees and newspapers set their own notice prices, so check both locally.
Changes also go back to the clerk. If you change your name, your home address or a business address in the county, or a new person joins the business, you file an additional acknowledged certificate setting out the change. Moving to, or opening in, another county means a certificate in that county too.
LLCs: the Secretary of State route
An Illinois LLC, or a foreign LLC admitted to do business in Illinois, can adopt an assumed name under 805 ILCS 180/1-20. Before trading under it, the LLC files an application for each assumed name with the Secretary of State, giving its true name, its state of formation, the fact that it intends to trade under an assumed name, and the name itself.
Two things don't count as an assumed name, so they don't need this filing: using a trademark or service mark the LLC owns or is licensed to use, and using a division name that doesn't contain the words limited, liability or company, provided the LLC also clearly discloses its true name.
Deadlines and forms for another filing are listed in the New York DBA guide.
What the LLC assumed name costs
The fee in 805 ILCS 180/50-10 depends on where you are in the five-year cycle, because the right to use the name runs until the LLC's anniversary month in the next year divisible by 5. As of October 2026:
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| When you file | Fee |
|---|---|
| Year ending in 0 or 5 | $150 |
| Year ending in 1 or 6 | $120 |
| Year ending in 2 or 7 | $90 |
| Year ending in 3 or 8 | $60 |
| Year ending in 4 or 9 | $30 |
| Renewal of each assumed name | $150 |
| Application to change an assumed name | $25 |
| Application to cancel an assumed name | $5 |
So an LLC filing a new assumed name in 2026 pays $120, and in 2027 it would pay $90. The cycle resets in 2030, when the name has to be renewed. There's one quirk in section 1-20(c): if you file in the 2 months just before your anniversary month in a year divisible by 5, your right runs to the following cycle instead.
A different state or filing type is covered in the Minnesota DBA guide.
Renewals and the late fee
Renewal happens with your annual report. Section 1-20(d) says the LLC renews within the 60 days before the right expires, for 5 years, by electing to do so on its annual report form and paying the renewal fee. If you miss it, the Secretary of State mails a notice of nonpayment, and if the fee plus a $100 late fee isn't paid within 60 days of that notice, the right to use the name ends, as of October 2026.
The Secretary of State also cancels the name if you file to change or cancel it, or if a foreign LLC's admission is revoked. Our Illinois LLC guide covers the annual report itself, and the DBA registration guide explains why a DBA isn't the same as owning the name.
Frequently asked questions
Where do I file a DBA in Illinois?
Sole proprietors and partnerships file an assumed name certificate with the county clerk in each county where they do business. LLCs file an application to adopt an assumed name with the Illinois Secretary of State.
Is a newspaper notice required for an Illinois DBA?
Yes, for county clerk filings. The notice runs once a week for 3 consecutive weeks, starting within 15 days of filing, and proof of publication goes to the clerk within 50 days.
How much does an LLC assumed name cost in Illinois?
It depends on the year: $150 in a year ending in 0 or 5, then $120, $90, $60 and $30 as the five-year cycle runs down, with a $150 renewal, as of October 2026, under 805 ILCS 180/50-10.
How often does an Illinois LLC renew its assumed name?
Every 5 years. The LLC elects to renew on its annual report within the 60 days before the right expires and pays the renewal fee.
What if an Illinois LLC misses its assumed name renewal?
The Secretary of State mails a notice of nonpayment. If the fee and a $100 late fee aren't paid within 60 days of that notice, the right to use the name ends.
