10/19/2026
Sales Tax Compliance: A Deadline Business Owners Shouldn’t Ignore
Running a business means keeping track of more than sales, customers, and day-to-day operations. Filing deadlines matter, too.
For Illinois businesses required to file Form ST-1, Sales and Use Tax Return, returns and payments are generally due by the 20th day following the end of the reporting period.
For the October 20, 2026 deadline:
- Monthly filers generally report September activity.
- Qualifying quarterly filers generally report July–September (Q3) activity.
Missing a filing or payment deadline can lead to penalties and interest. Good compliance starts with knowing what your business is required to file—and keeping those obligations organized.
Don’t let an important deadline get lost in the day-to-day of running your business.
The Hansford Firm helps Chicago-area business owners address business compliance, corporate governance, and other legal needs.
THE HANSFORD FIRM
30 North LaSalle Street, Suite 2121
Chicago, Illinois 60602
+1 (312) 448-6565
General information only and not individualized legal or tax advice. Filing frequency and requirements depend on the business and its Illinois Department of Revenue filing status.