Illinois economic nexus threshold
| Threshold | $100,000.00 |
|---|---|
| How the tests combine | the dollar test is the only test |
| Measured over | the trailing 12 months |
| Sales basis | gross sales, before any deduction |
| Do marketplace sales count toward it | no |
| In force since | 2026-01-01 |
| Rule last verified | 2026-07-31 |
Marketplace sales do NOT count toward the threshold
Illinois excludes marketplace-facilitated sales from the seller's own threshold. A sale where Amazon, Etsy, eBay or Walmart collected and remitted the tax does not count toward the Illinois figure.
StateWise still shows the total shipped into Illinois beside the measured figure, so the gap between the two is visible rather than implied.
This rule has changed, and the older version still governs the period it covered
| In force from | Until | Threshold | Measured over |
|---|---|---|---|
| 2023-01-01 | until 2026-01-01 | $100,000.00 or 200 transactions | the trailing 12 months |
| 2026-01-01 | still in force | $100,000.00 | the trailing 12 months |
A repeal does not reach backwards. A period is measured against the rule that was in force at the time, so a seller who met an older test met it, and a later change does not undo that. StateWise stores every crossing date with the rule version that produced it for exactly this reason. Kentucky is the worked example.
What "measured over" is doing
A threshold is a number and a period, and the period is the part most charts omit. Illinois measures over the trailing 12 months. Two sellers with identical annual sales can sit on opposite sides of this line because their sales fall differently inside that window.
Source
Sales Tax Institute, Economic Nexus State Guide (chart dated 2026-05-04)
https://www.salestaxinstitute.com/resources/economic-nexus-state-guide
Last verified 2026-07-31. StateWise publishes the verification date beside every rule because a threshold with no date on it is a claim a reader cannot evaluate.
What this page does not tell you
- Whether what you sell is taxable in Illinois.
- Anything about home-rule local taxes, which are outside this tool.
- What happens to an obligation after sales fall back below a threshold.
- Any deadline. Crossing a threshold is the point at which a state expects a seller to look into registering, and that decision has lasting consequences in both directions.
Related: the full jurisdiction table, how StateWise counts your sales, and what StateWise reads, and what it ignores.