What changes did Illinois make to its sales and use tax guidance?

Illinois updated its guidance to expand the definition of a “sale,” clarify who qualifies as a seller, and provide detailed rules and examples on determining physical presence and sourcing transactions.

How is the definition of “sale” expanded under the new guidance?

The definition now includes not only traditional retail transactions but also situations where tangible goods are transferred as part of a service, meaning more transactions may fall under taxable sales.

Who is considered a seller under the updated Illinois rules?

The updated guidance makes it clear that both retailers and service providers are considered sellers, which broadens the scope of businesses potentially subject to tax obligations.

What is the economic nexus threshold in Illinois?

Illinois applies a USD 100,000 economic nexus threshold for remote sellers and service providers without physical presence, requiring them to collect and remit tax if they exceed this amount in sales to Illinois customers.

How does Illinois determine where a sale is sourced?

Sales must be evaluated individually on a transaction-by-transaction basis, with the key factor being whether the sale originates inside or outside Illinois, which determines the applicable tax rate.

Why should businesses review their Illinois tax obligations now?

Because of the broader definition of “sale” and clearer nexus rules, businesses—especially service providers, may now fall within the scope of Illinois tax requirements and should reassess their compliance position.

Illinois Sales Tax Nexus Rules Updated for 2026

The Illinois Department of Revenue (DOR) has updated its sales and use tax guidance on how out-of-state retailers and service providers should determine whether they have a physical presence in Illinois and, if so, must collect and remit the appropriate taxes on sales made to customers in the state. In addition to clarifying key rules, the updated guidance provides numerous real-life scenarios as examples.

Key Updates from the Tax Guidance

The first notable change is the expansion of the definition of “sale” to include not only traditional retail transactions, leases, or rentals of tangible personal property, but also situations in which tangible goods are transferred to a customer as part of a service transaction. Additionally, it clarifies that the term seller includes both retailers and service providers.

The key question for both retailers and service providers is whether they have a physical presence in Illinois or meet the USD 100,000 economic nexus threshold. The threshold is established specifically for remote sellers and service providers, including marketplace facilitators, who have no physical presence in the state but still sell enough to local customers to trigger collection obligations.

In addition to explaining the differences between in-state tax rules and those for remote sellers, the updated guidance also provides new examples and charts to help businesses determine how a sale should be sourced and whether their activities create a physical presence in the state.

Regarding the sourcing, the DOR noted that determining where each sale is made must be done on a sale-by-sale or transaction-by-transaction basis rather than as a blanket determination. The DOR added that the key distinction is whether the sale originates in or out of Illinois, which then determines whether origin- or destination-based tax rates apply.

Conclusion

The updated guidance on sales and use tax from a nexus perspective is a valuable resource for both in-state and remote sellers. Given the broader definition of the term sale, businesses that have not recently reviewed their Illinois filing positions, particularly service providers who may not have previously considered themselves subject to these rules, should do so in light of these changes.

Source: Illinois Tax Department