Illinois Economic Nexus Threshold: $100,000 or 200 Transactions — SB 690 Rules Explained

SB 690: Illinois's Disjunctive Economic Nexus Threshold

Senate Bill 690, signed into law in 2018, amended the Illinois Use Tax Act (35 ILCS 105) to require remote sellers to collect Use Tax if they meet either of two thresholds during the preceding 12-month period: $100,000 or more in cumulative gross receipts from sales of tangible personal property to purchasers in Illinois, or 200 or more separate transactions for the sale of tangible personal property to purchasers in Illinois.

The law took effect on October 1, 2018 — roughly four months after the Supreme Court issued its landmark South Dakota v. Wayfair decision on June 21, 2018. Illinois moved faster than most states, reflecting the fact that the state had already been exploring remote seller collection requirements before Wayfair opened the constitutional door.

Sellers who exceed either threshold must register with the Illinois Department of Revenue (IDOR) and begin collecting Illinois Use Tax on sales to Illinois purchasers. The general state Use Tax rate is 6.25%, though local taxes can push effective rates higher in some jurisdictions. Registration requires obtaining an Illinois Business Tax (IBT) number through IDOR's MyTax Illinois portal.

How the Disjunctive “OR” Standard Works

The critical word in Illinois's threshold is “or.” Unlike conjunctive states such as New York (which requires both $500,000 in receipts and more than 100 transactions), Illinois triggers a collection obligation the moment either prong is satisfied. This matters in two distinct scenarios:

The transaction prong is especially significant for high-volume, low-ticket sellers. A seller of $15 phone cases who ships 200 orders to Illinois in a year has economic nexus — even though total revenue is only $3,000. This catches many Etsy sellers, Amazon third-party sellers with direct channels, and small e-commerce merchants who assume their low revenue keeps them below the radar. The disjunctive standard means volume alone can trigger the obligation.

The 12-Month Lookback Period

Illinois measures both prongs over the preceding 12-month period. This is a rolling window — not anchored to a calendar year, fiscal year, or quarterly cycle. At any point in time, you assess your Illinois sales activity over the prior 12 months to determine whether either threshold has been met.

The rolling nature means your nexus status can change at any time. A seller who exceeded $100,000 in Illinois sales between June 2025 and May 2026 has nexus as of the date they crossed the threshold. The obligation to register and collect does not wait for the end of a quarter or calendar year — it arises when the threshold is first exceeded.

This contrasts with states that use fixed lookback periods. California uses the prior calendar year, so nexus status resets and is assessed annually. New York uses its own four-quarter cycle. Illinois's rolling 12-month window requires continuous monitoring — especially for sellers with seasonal revenue patterns, where a strong Q4 can push the rolling total over $100,000 temporarily before it falls back below as older months drop off.

Origin-Based vs. Destination-Based Sourcing: Illinois's Compliance Asymmetry

This is where Illinois gets genuinely unusual — and where many remote sellers make costly mistakes. Illinois maintains two separate tax frameworks that apply different sourcing rules depending on whether the seller is located inside or outside the state:

The practical consequence: a Chicago-based retailer shipping a product to a customer in Springfield charges the Chicago ROT rate (origin-based). A remote seller in Oregon shipping the identical product to the same Springfield address charges the Use Tax rate based on the buyer's location (destination-based). The rates can differ significantly because ROT includes a broader set of local taxes tied to the seller's municipality.

For remote sellers, this is actually simpler in one respect — Use Tax rates are generally lower and have fewer local variations than ROT rates. But it creates headaches for tax automation software. Most tax engines default to destination-based sourcing for all states. For Illinois, that default is correct for remote sellers but wrong for in-state sellers. If you sell both from an Illinois warehouse and from out-of-state locations, your tax engine must apply two different sourcing methodologies within the same state — a configuration that many off-the-shelf solutions handle poorly without manual adjustment.

Retailers' Occupation Tax vs. Use Tax: Two Different Obligations

Understanding the ROT/Use Tax distinction is essential for Illinois compliance because they are separate taxes with different filing requirements, different returns, and different audit exposure.

The Retailers' Occupation Tax (ROT) is imposed on the privilege of selling tangible personal property at retail in Illinois. Despite the name, it is a tax on the seller, not the buyer — though sellers customarily pass the cost to purchasers. ROT is administered under 35 ILCS 120 and is filed on Form ST-1 (Sales and Use Tax and E911 Surcharge Return).

Use Tax is a complementary tax imposed on the buyer's use of tangible personal property purchased from a retailer outside Illinois. Under SB 690, remote sellers who meet the economic nexus threshold become responsible for collecting Use Tax on behalf of their Illinois purchasers. Remote sellers file Use Tax on Form ST-1 as well, but the sourcing and rate calculations differ from ROT filers.

The filing frequency depends on your tax liability. IDOR assigns new registrants a filing frequency — annual, quarterly, or monthly — based on estimated or actual liability. Most remote sellers with moderate Illinois volume start on quarterly filing and may be moved to monthly if their liability exceeds $20,000 per year. Returns are due on the 20th of the month following the reporting period.

IDOR Enforcement Letters: The Wayfair Non-Filer Program

The Illinois Department of Revenue has been among the more aggressive states in pursuing post-Wayfair compliance. IDOR operates an enforcement letters program specifically targeting remote sellers who appear to exceed the economic nexus threshold but have not registered for Illinois Use Tax.

The program relies on data from multiple sources: marketplace facilitator filings, payment processor records (1099-K data), shipping manifests, and information-sharing agreements with other state revenue departments. Using this data, IDOR identifies sellers whose Illinois sales volume likely exceeds $100,000 or 200 transactions and cross-references against its registration database. Sellers who appear unregistered receive a formal notice — typically a letter identifying them as a potential non-filer and requesting voluntary registration.

The letters are not merely advisory. Sellers who ignore them risk:

• Formal assessments — IDOR can estimate the tax you should have collected and issue a notice of tax liability, which accrues interest from the original due date
• Penalties — late filing penalties of 2% per month (up to a maximum), plus a potential negligence penalty of 20% if IDOR determines the failure to register was willful
• Compounding interest — Illinois charges interest on unpaid tax from the date the tax should have been collected, not from the date of the assessment. For sellers who have been over the threshold for years, the interest alone can be substantial

If you receive an IDOR enforcement letter, the most effective response is prompt voluntary registration. IDOR has historically offered more favorable terms — including potential penalty abatement — to sellers who come into compliance voluntarily after receiving a notice, compared to those who are formally assessed after ignoring one.

Marketplace Facilitator Law and the ROT/Use Tax Split

Illinois's marketplace facilitator law took effect January 1, 2020 — and was substantially restructured by the Leveling the Playing Field for Illinois Retail Act on January 1, 2021. The 2021 amendments are critical because they applied the ROT/Use Tax split to marketplace facilitators themselves, not just to direct remote sellers. For multi-channel sellers, this creates an Illinois compliance picture that does not exist in any other state.

Which Platforms Are Marketplace Facilitators in Illinois

Once a platform exceeds $100,000 in cumulative IL gross receipts or 200 IL transactions over the prior 12 months, it is required to collect and remit on behalf of its third-party sellers. The major qualifying platforms:

• Amazon, eBay, Etsy, Walmart Marketplace — collect on all IL-bound third-party transactions
• Mercari, Poshmark, Depop, StockX, Reverb, eBid — qualify and collect
• DoorDash, Uber Eats, Grubhub — qualify as facilitators for prepared food orders
• Airbnb, Vrbo — collect IL hotel occupancy tax on facilitated stays

Shopify, BigCommerce, WooCommerce, and Squarespace Commerce are NOT marketplace facilitators — they are hosted commerce platforms. Sales through your Shopify store count toward your individual SB 690 threshold and are your own direct collection obligation once you register.

The 2021 Amendment: Why Amazon Now Charges ROT, Not Just Use Tax

Before January 1, 2021, marketplace facilitators in Illinois collected only Use Tax on facilitated sales — a flat 6.25% destination-based rate. After Leveling the Playing Field took effect, the law treats marketplace facilitators as if they are the retailer for Illinois ROT purposes whenever the facilitator (or its third-party seller) maintains a physical place of business in Illinois. The practical effect: if your FBA inventory is stored in an Illinois Amazon warehouse, Amazon must collect the full destination-based Retailers' Occupation Tax(state 6.25% + local rates, often 9-11% total in Chicago and Cook County) on your IL orders, not just the 6.25% Use Tax. This change closed a significant tax-rate arbitrage that had favored remote-only sellers.

How Marketplace Sales Affect Your Individual SB 690 Threshold

Sales for which a marketplace facilitator collected and remitted are excluded from your individual $100K/200-transaction threshold calculation. But Illinois applies this exclusion strictly — you must be able to document, with marketplace tax-collected reports, that the platform actually remitted. The threshold math:

• $400K Amazon + $30K Shopify into IL: No registration required. Amazon-collected sales are excluded; your direct revenue is $30K with under 200 IL transactions.
• $400K Amazon + $80K Shopify into IL, 250 Shopify transactions: Registration required — the disjunctive transaction count alone (250 > 200) is met on the direct channel.
• $50K Amazon + $50K Etsy + $40K Shopify into IL: No registration. Marketplace-collected sales excluded; $40K direct is under both prongs.
• $0 Amazon + $120K Shopify into IL: Registration required ($120K > $100K on direct channel alone).

FBA Inventory in IL: Marketplace Coverage Does Not Erase Physical Nexus

Amazon operates fulfillment centers in Illinois (Joliet MDW2, Aurora MDW6, Romeoville MDW4, Monee MDW7, and others). If your FBA inventory is stored in any of these, you have physical presence nexus in Illinois regardless of your direct sales volume. You must register and file Form ST-1 — even though your tax due on Amazon orders will typically be $0 because Amazon already collected and remitted. IDOR enforcement letters specifically cross-reference FBA inventory data and unregistered sellers, so the cost of ignoring registration is high.

Reporting Marketplace Sales on Form ST-1

Multi-channel Illinois filers report total gross receipts on Schedule A of Form ST-1 and then deduct facilitator-collected sales on Schedule A, Line 17 ("Sales for which I am not responsible for tax because a marketplace facilitator is collecting and remitting"). Tax is calculated only on the net taxable receipts. Keep marketplace 1099-K and tax-collected detail reports as audit documentation — IDOR has been reconciling reported Line 17 deductions against marketplace remittance filings since 2022.

For the cross-state comparison of which platforms qualify and where the coverage gaps are, see the marketplace facilitator laws by state hub.

Illinois vs. Other $100K-Threshold States

Illinois shares the $100,000 revenue threshold with the majority of states that enacted economic nexus laws post-Wayfair. But several features distinguish Illinois from its $100K peers.

The origin-vs-destination sourcing split and the ROT/Use Tax duality are what make Illinois uniquely complex among $100K-threshold states. Most states impose a single sales tax with destination-based sourcing for all sellers. Illinois's two-tax framework means sellers with both Illinois-based and remote operations must manage two different tax regimes within the same state — a compliance burden that no other major $100K-threshold state imposes. For the full comparison of thresholds across all states, see the sales tax nexus thresholds by state hub.