Yes—but only in a specific situation. Illinois Department of Revenue (IDOR) may assess a 15% tax on the gross receipts of destination-based sales assigned to an undetermined location when the seller fails to provide enough information, schedules, or supporting documents to determine where the sale should be sourced. The 15% rate is not Illinois’s normal statewide rate for every sale with an unclear address; it is an undetermined-location assessment used when required destination information is missing.
For a properly documented destination sale, Illinois generally applies the combined state and local retailers’ occupation tax rate in effect where the tangible personal property is shipped, delivered, or picked up by the purchaser. Beginning January 1, 2026, the 200-transaction remote-retailer threshold no longer applies; the relevant Illinois threshold is generally $100,000 or more in cumulative gross receipts from sales of tangible personal property to Illinois purchasers during the preceding 12-month period. The exact position depends on your circumstances—confirm with IDOR, or talk to Sales Tax Compliance USA and we will check it for you.
Key takeaways
- The 15% figure is an undetermined-location assessment, not Illinois’s normal rate for every sale.
- For a properly documented remote sale, source the tax to the Illinois delivery or possession destination.
- Beginning January 1, 2026, the remote-retailer threshold is generally $100,000 in preceding-12-month Illinois tangible personal property receipts; the 200-transaction threshold no longer applies.
- Use IDOR’s address-based Tax Rate Finder and location codes when preparing Form ST-1 and Form ST-2.
- Missing destination records can lead to a 15% assessment on gross receipts, interest, and potentially additional penalties.
What destination-based sales tax means in Illinois
Illinois uses destination-based sourcing for qualifying sales made by remote retailers and marketplace facilitators. The tax is calculated using the total state and local retailers’ occupation tax rate in effect at the Illinois destination: the address where the tangible personal property is shipped, delivered, or where the purchaser takes possession.
This is different from origin sourcing. Origin sourcing looks to the Illinois inventory location from which an order is fulfilled or where selling activity occurs. A remote retailer with no Illinois physical presence generally uses the customer’s Illinois destination when the seller meets the applicable tax-remittance threshold. A seller with Illinois inventory or other physical presence may need to analyze whether the sale is sourced under origin or destination rules.
For example, an online order shipped from outside Illinois to a customer in Illinois is not assigned a single statewide local rate merely because the customer is in Illinois. The seller must identify the destination’s local taxing jurisdictions and apply the rate for that location. Product taxability, exemptions, fulfillment arrangements, and the seller’s Illinois status can also affect the result.
When Illinois applies the 15% undetermined-location rate
IDOR applies the 15% undetermined-location rate when a destination-based sale cannot be assigned to the correct Illinois location because the taxpayer has not provided sufficient information, schedules, or supporting documents. IDOR describes the assessment as applying to the gross receipts of sales assigned to undetermined tax locations.
This means the 15% figure is not a standard rate that sellers should charge every Illinois customer. It is a consequence of failing to support the destination used for reporting. A seller should therefore not solve an address-data problem by automatically charging 15% on ordinary orders. The correct approach is to collect and retain destination information, determine the applicable location code and rate, and report the sale to that location.
IDOR states that the 15% undetermined-location rate may be used during an audit for periods under audit, including periods before January 2026. That makes historical order, shipping, and location data important even if the seller’s current checkout process has been corrected.
What destination information sellers must collect
The core record is the purchaser’s exact delivery or possession location. IDOR’s recordkeeping guidance identifies the customer name and exact address, including street number, street address, city, county, state, and ZIP Code, for the location to which the property is shipped or delivered or where the purchaser takes possession.
For ecommerce businesses, the order record should also connect that address to the transaction: order number, order date, item or SKU, taxable and exempt amounts, shipping charges where relevant, tax collected, refund or cancellation information, and the fulfillment or shipment record. Keep the carrier record, tracking information, warehouse or inventory source, and any delivery or pickup documentation that helps establish what happened.
Address quality matters. IDOR instructs sellers to use its MyTax Illinois Tax Rate Finder’s address search, validate the address so the nine-digit ZIP Code is displayed properly, identify the applicable rate, and obtain the corresponding location code. If an order has an incomplete, undeliverable, or conflicting address, resolve the information before finalizing the tax treatment where practical.
Illinois thresholds for remote retailers
Beginning January 1, 2026, Illinois uses a $100,000 cumulative gross-receipts threshold for a remote retailer selling tangible personal property to Illinois purchasers. The 200-separate-transaction threshold that applied through December 31, 2025 was removed for the current rule. IDOR instructs retailers to test the $100,000 threshold on a quarterly basis using the preceding 12-month period.
A remote retailer that meets the threshold generally must register with IDOR, collect destination-based retailers’ occupation tax on applicable sales, file Illinois returns, and remit the tax. A retailer with Illinois physical presence may have obligations regardless of the remote-retailer threshold. Product-specific rules can also change the analysis; for example, the treatment of digital products and SaaS requires a separate review, as discussed in SaaS and digital product sales tax in Illinois.
Threshold calculations should be based on the categories Illinois uses, not simply on a marketplace dashboard’s “Illinois sales” total. Review gross receipts, returns, cancellations, exempt transactions, marketplace sales, direct sales, and fulfillment arrangements consistently. For a broader nexus analysis, see economic nexus in Illinois.
What if you previously met the 200-transaction threshold?
If a seller previously met the 200-transaction threshold but did not meet the $100,000 gross-receipts threshold, IDOR instructs the seller to review the relevant 12-month period ending December 31, 2025 and determine whether the $100,000 threshold was met. As of January 1, 2026, IDOR states that it will automatically change the registration status of a taxpayer in that situation to “voluntary use tax.”
That status change does not eliminate the need to examine other facts. A seller may still have Illinois physical presence, may later meet the $100,000 threshold, or may have obligations involving a different tax type or taxable product. Check the seller’s IDOR account and transaction history rather than assuming that a status change settles every Illinois obligation.
If your business crossed the old threshold, collected tax, or filed returns based on incomplete historical information, review the prior periods before changing procedures. The exact position depends on your circumstances—confirm with IDOR, or talk to us and we will check it for you.
Marketplace facilitator rules and common sales channels
Illinois marketplace facilitator rules generally place collection and remittance responsibility on a qualifying marketplace facilitator for sales made through the marketplace, including sales made on behalf of marketplace sellers. The tax is based on the purchaser’s destination. The facilitator may therefore collect the Illinois state and local tax while the marketplace seller separately evaluates registration, reporting, exemption documentation, inventory, and direct-channel obligations.
Inventory stored at a marketplace facilitator’s Illinois location may not by itself create physical presence for a marketplace seller when it is used exclusively to fulfill marketplace orders under the Illinois rules. If the inventory is used for the seller’s own orders, or for both the seller’s direct orders and marketplace orders, the physical-presence analysis can differ. Amazon FBA sellers should review Amazon FBA sales tax in Illinois before assuming the marketplace handles every obligation.
Marketplace collection also does not make destination data irrelevant. Sellers should retain marketplace settlement reports, order-level destination information, tax collected, refunds, and facilitator tax documents. For a detailed review of these responsibilities, see marketplace facilitator rules in Illinois.
Registration, location codes, and Illinois filing
Remote retailers that meet the applicable threshold register with IDOR through MyTax Illinois by submitting the business registration application. IDOR’s instructions require destination-based sales to be separated on Form ST-2, Multiple Site Form, according to the local tax jurisdiction where the customer is located. For remote retailers and marketplace facilitators, the “site” is the Illinois destination where the item is delivered—not necessarily the seller’s warehouse or the customer’s street address as a registered business site.
Use IDOR’s Tax Rate Finder to search the destination address, validate the address, identify the rate, and obtain the 11-character location code. IDOR instructs sellers to use the location code for the corresponding local-government taxing district when adding a location and reporting on Form ST-2, rather than using the customer’s address as the tax-site location.
In practical terms, your filing workpaper should map each taxable order or reliable order grouping to the correct destination jurisdiction, location code, taxable receipts, tax collected, and any deductions or exemptions. Form ST-1 reports the return-level activity, while Form ST-2 provides the multiple-site detail needed to support destination-based reporting. Filing frequency and return due dates are assigned by IDOR and should be confirmed in the seller’s account and current instructions.
Penalties and the cost of missing destination data
The 15% undetermined-location tax can be financially significant because it applies to gross receipts assigned to an undetermined location, not merely to an amount of tax that the seller failed to collect at a known local rate. IDOR states that, beginning January 1, 2026, the 15% assessment applies in place of the unprocessable-return penalty for the missing-location issue described by the department.
That does not mean a seller is protected from every other penalty. IDOR states that standard penalties under the Uniform Penalty and Interest Act may still apply where appropriate, including when a return is otherwise unprocessable. The department also states that the undetermined-location tax is subject to penalties and interest and that additional penalties may be assessed.
Separate recordkeeping consequences can apply. IDOR identifies a $1,000 penalty for a first failure to keep required books and records and $3,000 for each subsequent failure. Because the interaction of assessments, penalties, interest, filing errors, and audit findings depends on the facts, do not estimate exposure from the 15% rate alone. Review the notice or filing position with IDOR or a qualified tax professional.
Records that support destination-based sales
IDOR requires retailers to keep records of sales, purchases, inventory changes, shipments, accounts receivable, accounts payable, summaries or ledger accounts, return workpapers, and filed returns. For destination-based sales, the most important evidence usually includes the purchaser’s exact address, the destination used for sourcing, the location-code lookup or mapping, shipment and delivery records, and documentation supporting the location from which the property was shipped.
Keep records that distinguish taxable and nontaxable sales and support deductions. For exempt or resale sales, retain the purchaser information, transaction date, receipt amount, transaction character, and exemption or resale documentation. The article resale and exemption certificates in Illinois explains why those documents should be collected and matched to the relevant transactions.
Not sure how this applies to your business? We handle US sales tax registration, filing and remittance for ecommerce sellers as a fully managed service, for one fee. Book a free consultation and we will review your own position with you.
IDOR’s published guidance generally requires records documenting receipts for the reporting period to be kept for three and one-half years after filing the original or amended return. If IDOR has issued a notice of tax liability or final notice of tax due, keep the relevant records until the liability is finalized or discharged. Preserve the original electronic files and an export that can be reviewed by order, date, destination, jurisdiction, location code, taxable amount, tax rate, and tax collected.
Illinois destination-based sales: the rule, the data, and the reporting consequence
| Situation | Sourcing or collection result | Seller action |
|---|---|---|
| Qualifying remote sale with a complete Illinois delivery address | Use the combined state and local destination rate for the delivery or possession location. | Validate the address, determine the location code, calculate tax, and retain the order and shipment records. |
| Destination-based sale with insufficient location information | IDOR may assign the sale to an undetermined location and assess 15% of gross receipts. | Reconstruct the destination if possible and preserve supporting schedules and documents. |
| Remote retailer meeting the current $100,000 threshold | Generally subject to Illinois destination-based ROT on applicable tangible personal property sales. | Register with IDOR, collect, file Form ST-1 and required ST-2 detail, and remit. |
| Remote retailer below the current threshold with no Illinois physical presence | The remote-retailer destination collection obligation may not apply under the threshold rule. | Continue monitoring the preceding 12-month receipts and review physical presence and product-specific rules. |
| Marketplace sale handled by a qualifying facilitator | The facilitator generally collects and remits tax on marketplace sales at the purchaser’s destination rate. | Reconcile facilitator reports and retain order-level destination and tax records; analyze direct sales separately. |
| Sale fulfilled from Illinois inventory or involving other Illinois physical presence | Origin-versus-destination treatment may differ from a purely remote sale. | Review fulfillment, inventory ownership, selling activity, and registration facts before filing. |
| Exempt or resale transaction | Tax may not be due if the exemption is valid and properly documented. | Match the exemption or resale certificate to the transaction and keep it with the sales records. |
Frequently asked questions
Are Illinois undetermined-destination sales taxed at 15 percent?
They can be. IDOR may assess 15% of gross receipts for destination-based sales assigned to an undetermined location because the seller failed to provide sufficient location information or supporting documents. It is not the ordinary tax rate for every Illinois sale with an unclear address.
What is destination-based sales tax in Illinois?
It is the combined state and local retailers’ occupation tax rate in effect where tangible personal property is shipped, delivered, or picked up by the purchaser. The seller must identify the Illinois destination and report the sale to the applicable local tax jurisdiction.
When does Illinois apply the 15% undetermined location tax rate?
IDOR applies it when required information, schedules, or supporting documents are missing or insufficient to determine the proper destination location for a destination-based sale. IDOR also states that the rate may be used in an audit for periods under audit, including periods before January 2026.
What information must sellers provide to determine an Illinois tax location?
The seller should retain the purchaser’s name and exact delivery or possession address, including street, city, county, state, and ZIP Code. Shipment, delivery, pickup, fulfillment-source, order, and tax-calculation records help connect that address to the reported location code and tax rate.
How do Illinois remote-retailer thresholds affect registration and filing?
Beginning January 1, 2026, the key remote-retailer threshold is generally $100,000 or more in cumulative gross receipts from sales of tangible personal property to Illinois purchasers during the preceding 12-month period. A seller meeting the threshold generally must register, collect destination-based tax, file returns, and remit the tax; physical presence can create obligations independently.
What happens if a seller previously met the 200-transaction threshold but no longer meets the $100,000 threshold?
The 200-transaction threshold no longer applies under the current rule. IDOR states that a taxpayer in that situation should review the relevant period and that its registration status will be automatically changed to voluntary use tax as of January 1, 2026. The seller should still review physical presence, later receipts, direct sales, and other tax obligations.
Can Illinois assess additional penalties when the 15% undetermined rate applies?
Yes, potentially. The 15% assessment replaces the specified unprocessable-return penalty for the missing-location issue, but IDOR states that standard penalties, interest, and additional penalties may still apply when the facts support them. Separate penalties may also apply for failing to keep required books and records.
What records should sellers keep to support Illinois destination-based sales?
Keep order-level sales data, the purchaser’s exact destination address, shipment and delivery evidence, fulfillment-source records, tax-rate and location-code workpapers, exemption or resale documents, marketplace reports, refund records, inventory records, filed returns, and reconciliation schedules. IDOR’s general guidance says receipt records are generally retained for three and one-half years after filing, subject to longer retention when a liability notice remains unresolved.
Official sources
- https://tax.illinois.gov/research/taxinformation/sales/destination-based-sales-tax-assistance.html
- https://tax.illinois.gov/research/publications/bulletins/fy-2026-12.html
- https://tax.illinois.gov/research/taxinformation/sales/rot.html
- https://tax.illinois.gov/research/publications/pubs/overview-of-destination-based-sales-tax.html
- https://tax.illinois.gov/forms/sales/salesandusetax/st-1-instructions.html
- https://tax.illinois.gov/forms/sales/salesandusetax/st-2-instructions.html
Related reading
- Amazon Fba Sales Tax in Illinois
- Back sales tax and penalties in Illinois
- Economic nexus in Illinois
- Marketplace facilitator rules in Illinois
- Our sales tax compliance services
Getting this handled
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Reviewed by Paul le Roux, CA(SA). Sales Tax Compliance USA handles US sales tax registration, filing and remittance for cross-border and domestic ecommerce sellers as a fully managed service.
This article is general information for educational purposes and does not constitute legal or tax advice. Sales tax rules change and depend on your specific facts. Consult a qualified tax professional about your own position.