Registration guide
Should I register for sales tax in Illinois?
Before you register for sales tax in Illinois, check whether you actually have to. Registering when you don't owe just adds a recurring return — here's exactly when Illinois requires it.
- Economic threshold
- $100,000 in sales
- Measured over
- preceding 12 months, evaluated quarterly on the last day of March, June, September, and December
- In effect since
- October 2018
- Marketplace sales count?
- No
- Registration fee
- Free
When you must register
You must register in Illinois if you have physical presence there (inventory, staff, an office) or you cross $100,000 in sales (preceding 12 months, evaluated quarterly on the last day of March, June, September, and December). Below that, with no physical presence, you generally don't have to.
Nexus & savings calculator
Estimate whether you still have nexus in Illinois — and what canceling could save.
Illinois no longer counts transactions — only sales matter here.
- Physical presence
- Sales over $100,000
- Transactions (not counted here)
Based on these numbers you likely no longer have nexus in Illinois. You can usually deregister after clearing the trailing-nexus window and filing your final return.
Trailing nexus: Illinois has limited or no trailing-nexus window — you can generally deregister once your nexus has ended and final returns are filed.
You could stop paying
$600/ yr
Estimate only — general education, not tax advice. Confirm with Illinois's tax authority before you register or deregister.
When registration is required in Illinois
Illinois requires registration once you cross $100,000 in sales, measured over preceding 12 months, evaluated quarterly on the last day of March, June, September, and December. Illinois used to trigger nexus at 200 transactions but removed that count in January 2026 — only the sales figure matters now.
Physical presence registers you regardless of sales. Standard physical nexus triggers include: owning/leasing/maintaining an office, warehouse, distribution center, or other place of business in Illinois; having employees, agents, or representatives operating in Illinois (including remote workers based in Illinois); storing inventory in Illinois fulfillment centers (including Amazon FBA).
The marketplace nuance most sellers miss
If you sell only through a marketplace like Amazon or Etsy, the marketplace facilitator generally collects and remits Illinois tax for you, so you may not need your own permit. In Illinois, facilitated sales do not count toward your own threshold.
How to register in Illinois
Register through MyTax Illinois, which is free. Illinois is not a Streamlined Sales Tax (SST) member state.
Don't over-register
Most over-registered sellers signed up defensively across many states after 2018. If you're under Illinois's threshold with no physical presence, registering early just creates a recurring zero-dollar return. Register when you truly must — and track the states where you can stop.
Where TrailingZero fits
TrailingZero connects to your store read-only, maps where you actually have nexus state by state, and flags when you genuinely cross Illinois's threshold — and where you've already dropped below and can deregister. During any wind-down it can file the zero-dollar returns so nothing lapses — and you only pay for the states you genuinely keep. Run a free audit anytime; this page is free education either way.
Illinois Should I register FAQ
- Do I need to collect sales tax in Illinois?
- Only once you have nexus: physical presence, or crossing $100,000 in sales over preceding 12 months, evaluated quarterly on the last day of March, June, September, and December. Under that, with no physical presence, you generally don't.
- Does Illinois still count transactions?
- Illinois used to trigger nexus at 200 transactions but removed that count in January 2026 — only the sales figure matters now.
- Do marketplace sales count toward the Illinois threshold?
- No — facilitated sales do not count toward your own threshold in Illinois.
- Is this tax advice?
- No. This page is general education built from public sources and the rules change often. Confirm your specific situation with the state's tax authority or your accountant before you register or deregister.
More on Illinois sales tax
See what you can stop paying in Illinois
Run a free audit and see which registrations you can drop — in minutes, no card required.
Other states
See all states →Sources
Primary sources reviewed for this page. Data current as of June 2026.
- https://tax.illinois.gov/research/publications/bulletins/fy-2026-12.html
- https://www.salestaxinstitute.com/resources/illinois-economic-nexus-update-no-transaction-threshold
- https://www.salestaxinstitute.com/resources/illinois-enacts-economic-nexus-legislation
- https://www.avalara.com/blog/en/north-america/2025/06/illinois-drops-transaction-threshold-offers-tax-amnesty.html
- https://taxcloud.com/sales-tax-radar/illinois-eliminates-transaction-threshold-2026/
- https://taxcloud.com/sales-tax/illinois/
- https://tax.illinois.gov/businesses/registration.html
- https://tax.illinois.gov/businesses/close.html
TrailingZerois software, not a CPA or law firm, and this page is general education — not tax or legal advice. State rules and thresholds change frequently; confirm your situation with the state's tax authority or your accountant before you register or deregister. See how we research and review this data in our editorial & accuracy policy.