Learn what the Illinois Uniform Deceptive Trade Practices Act bans, who it covers and what a court can order, with slides, a table and a checklist for owners.
Last reviewed October 29, 2026 · General information, not legal advice
General information only, not legal advice. CPA Tax Payroll and Accounting Corp is a CPA firm, not a law firm. Laws change: confirm with the official source or a licensed attorney before you act. Read the full notice.
The Illinois Uniform Deceptive Trade Practices Act (UDTPA), found at 815 ILCS 510, lists 12 business practices that Illinois treats as deceptive. They range from passing off one business's goods as another's to false claims about price cuts. The Act dates from 1965, and its remedy is a court order rather than a fine. This page is for owners of small businesses, freelancers and professionals who name, advertise and price what they sell in Illinois. Our Illinois state page covers state tax topics.
Slide show: The Deceptive Trade Practices Act in seven slides
What it is
Illinois's list of deceptive trade practices, at 815 ILCS 510, approved in 1965.
Who it covers
Any business, vocation or occupation. The text sets no size threshold.
The core rule
The law bars confusing customers about who a seller is, where goods came from or what they are.
The key number
12 listed practices, from passing off to false price-reduction claims.
The deadline
The Act's text states no time limit. An attorney can say how time limits apply to a claim.
The remedy
An injunction. This Act has no damages or penalty; fees and costs come only for willful conduct.
A practical tip
Keep the proof behind every "sale", "new" and "certified" claim.
Who is covered
Question
What the statute says
Who can violate it
Any "person" (an individual, corporation, government agency, trust, partnership, association or other legal or commercial entity) acting in the course of business, vocation or occupation (Secs. 1(5), 2(a))
Who can sue
A person likely to be damaged by another's deceptive practice (Sec. 3)
Competition
The plaintiff need not prove competition or actual confusion (Sec. 2(b))
Exclusions
Conduct that follows orders, rules or a statute administered by a federal, state or local agency; publishers, broadcasters and printers who spread material without knowing it is deceptive; two narrow carve-outs tied to 1965 (cases then pending, and older good-faith use of a mark or name) (Sec. 4)
Size threshold
None
How it touches your taxes and payroll
The Act has no tax or payroll text. For a CPA's clients the link is advertising: claims such as "up to 50% off", "new" and "original" are tested under Sec. 2(a)(6) and (11). Advertising spend itself is a books-and-records topic, covered in our guide to business expense deductions. A new business choosing its name can start with our business formation page.
