This blog was last updated on November 19, 2025

This year has brought change to the Illinois sales tax nexus rules. In addition to the South Dakota v. Wayfair, Inc. decision, the economic nexus threshold will change for marketplace and remote sellers on January 1, 2026. Illinois will eliminate the 200-transaction threshold for establishing economic nexus for sales tax purposes. Going forward, both remote retailers and marketplace facilitators will be subject to economic nexus rules based solely on whether their cumulative gross receipts from sales to Illinois purchasers exceed $100,000 over the previous 12 months.

Enforcement date:
January 1, 2026

Sales/transactions threshold:
$100,000.

Measurement period:
Preceding 12 months calculated on the last day of March, June, September, and December.

Included transactions/sales:
Sales of tangible personal property.

When You Need to Register Once You Exceed the Threshold:
The end of the quarter in which the threshold is met.

Summary: Remote sellers with no physical presence in Illinois that meet either of the above thresholds must register with the Illinois Department of Revenue to begin collecting and remitting Illinois Use Tax for sales made to Illinois purchasers. Marketplace facilitators must collect Retailer’s Occupation Tax when they facilitate gross sales of $100,000 for the sale of tangible personal property to purchasers in Illinois during the previous 12 months.

Remote sellers that make sales to Illinois purchasers from locations outside must register with the Illinois Department of Revenue (IDOR) to collect and remit Illinois Use Tax on those sales if they fall within the definition of a “retailer maintaining a place of business in this State.” Businesses with sales “outside the marketplace or if the marketplace facilitator is not required to collect Illinois Use Tax because it does not meet either of the marketplace thresholds, sellers must collect and remit Illinois Use Tax on those sales if they are a ‘retailer maintaining a place of business’ in Illinois (i.e., they have nexus, including, but not limited to, Wayfair [economic] nexus),” the IDOR states.

Illinois Sales Tax Resources: Reach out to our team of experts for more information on how Illinois sales tax nexus rules potentially apply to your business. Additionally, check out our interactive sales tax nexus map to see how other states were impacted by Wayfair.