Illinois assumed name filing guide

Illinois uses the term "assumed name" for what most businesses call a DBA or "doing business as," and it splits the filing by entity type across two different offices.

Individuals and general partnerships that conduct or transact business under any name other than the real names of the owners must file a certificate under the Assumed Business Name Act (805 ILCS 405) with the County Clerk of each county where the business is conducted or transacted.

That Act expressly does not apply to corporations, limited liability companies, limited partnerships, or limited liability partnerships; those entities instead register assumed names with the Illinois Secretary of State under their own governing statutes — Section 4.15 of the Business Corporation Act for corporations and Section 1-20 of the Limited Liability Company Act for LLCs.

County-level filings carry a newspaper publication requirement: notice must run in a newspaper of general circulation in the county once a week for three consecutive weeks, starting within 15 days of filing, with proof filed within 50 days, or the certificate is void.

State-level assumed names run in five-year cycles tied to the entity's anniversary month.

The Cook County Clerk describes an assumed name as any name other than the name of the individuals who own or operate the business, so a business using the owner's full name generally does not have to file at the county level.

Sole proprietors and general partnerships file with the county clerk where the business operates.

Cook County, for example, offers an online application for its $50 registration fee paid by credit card or e-check, after which the printed application must be signed by the owners, notarized, and mailed or delivered to the Clerk's office; in-person filing is available at the Vital Records office in the County Building at 118 N.

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Fees and procedures are set by each county clerk, so filers outside Cook County should check their own county clerk's office.

LLCs file Form LLC-1.20, Application to Adopt, Change, or Cancel an Assumed Name, with the Secretary of State's Limited Liability Division in Springfield, and domestic and foreign LLCs in good standing may also adopt an assumed name electronically through the Secretary of State's online system.

Corporations file Form BCA-4.15/4.20, Application to Adopt, Change or Cancel an Assumed Corporate Name, submitted in duplicate to the Department of Business Services in Springfield by check or money order.

The state adoption fee varies by the year of filing: $150 in years ending in 0 or 5, stepping down to $30 in years ending in 4 or 9.

Expedited requests must be made in person at the Springfield or Chicago office.

State-level assumed names in Illinois run on five-year cycles.

For an LLC, the right to use an assumed name is effective from the date the application is filed until the first day of the company's anniversary month in the next calendar year evenly divisible by five, and the same structure applies to corporations.

Renewal happens by election on the entity's annual report within the 60 days before expiration, for another five-year period, with the renewal fee prescribed by the governing act; under Section 1-20(h) of the LLC Act, an LLC that misses the renewal fee is notified by mail, and if the fee together with a $100 late fee is not paid within 60 days after the notice is mailed, the right to use the assumed name ceases.

Both entity types use the same application form to change or cancel an assumed name: the LLC form states a $25 fee to change and a $5 fee to cancel.

At the county level, the Assumed Business Name Act requires a new acknowledged certificate whenever the registrant's name, residence address, or business address in the county changes, when a person is added to the business, or when the business moves to or expands into another county — and the publication steps must be repeated for those filings.

County clerks also handle dissolution of an assumed business name registration.

Start with the free official path, which depends on your entity type.

If you operate as a sole proprietorship or general partnership, contact the county clerk in each Illinois county where you conduct business — the Cook County Clerk, for one, publishes its application, its $50 fee, and the publication steps online — and remember the statutory newspaper notice and proof-of-publication deadlines, because the certificate is void without proof.

If you operate an LLC or corporation, download Form LLC-1.20 or Form BCA-4.15/4.20 from the Illinois Secretary of State, or, for an LLC in good standing, use the Secretary of State's online assumed-name adoption system, and budget the sliding adoption fee that matches the current year.

County clerk pages for measured Illinois counties are linked from this site where available.

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