Small business laws in plain English: federal, Illinois and Cook County
One short page for each of 36 laws that can reach a small business in Aurora, Naperville and Chicagoland, with slides, tables, charts and a checklist. General information, not legal advice.
Prepared by Prem Tax and Accounting Corp. Last checked against official sources on October 29, 2026.
Business law comes in layers. A shop in Naperville can answer to federal law, Illinois law and, with a site or staff in Cook County, county ordinances too. This section gives each of 36 laws one short page from a CPA firm: what it is, who it covers, the numbers with their years and a checklist. There are 14 federal laws, 18 Illinois laws and 4 Cook County laws.
How the section is organised
Each law page opens with a short-version box, then a slide show, tables, our named checklist and common mistakes. Two extras help you cross-check: which laws apply by employee count and the disclaimer and terms of use, which you should read before relying on any page.
Which level of law applies to what
| Level | Who sets and enforces it | Typical topics | Where it applies |
|---|---|---|---|
| Federal | Congress; agencies such as the Department of Labor, EEOC, OSHA, IRS and FTC | Pay, job discrimination, safety, payroll tax, marketing | Every state, Cook County included |
| Illinois | General Assembly; Departments of Labor, Human Rights and Revenue | Entities, wage payment, human rights, sales and income tax | Work and business in Illinois |
| Cook County | County Board; Commission on Human Rights; Department of Revenue | Paid leave, minimum wage, human rights, licensing | Cook County only; Chicago and many suburbs have their own rules |
Common questions
Do all three levels apply to my business?
Federal law can reach a business in every state, each law with its own coverage tests. Illinois law can reach work and business in Illinois. Cook County law reaches work and premises inside the county, and DuPage, Kane, Will and Kendall counties generally follow state law.
What if two levels set different minimum wages?
A covered worker gets the higher federal or state rate. In 2026 that is Illinois at $15.00 an hour for employers with four or more employees, against the federal $7.25. Cook County sets $15.40 since July 1, 2026, where its ordinance applies.
Is this legal advice?
No. We are a CPA firm, not a law firm. These pages are general information, and the [disclaimer](/small-business-laws/disclaimer/) explains the limits.
Official sources
- U.S. Department of Labor: Wage and Hour Division
- U.S. Equal Employment Opportunity Commission: Small business
- Illinois General Assembly
- Cook County Commission on Human Rights
- U.S. Department of Labor: State minimum wage laws
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