Understanding ecommerce sales tax is essential for online sellers. Since the 2018 South Dakota v. Wayfair decision, states can require remote businesses to collect and remit sales tax when they meet economic-nexus thresholds, even without a physical presence.
Rates, thresholds, filing requirements, and product-taxability rules differ across jurisdictions. This guide provides an overview for 2026 planning; confirm current requirements with the relevant tax authority.
What Is Ecommerce Sales Tax?
Ecommerce sales tax is tax imposed on taxable goods and services sold through online platforms. Online sellers must navigate state and local laws that vary based on the seller, buyer, product, delivery method, and sales channel.
Key Components of Ecommerce Sales Tax
- Sales-tax permits: Businesses generally need a permit before collecting tax in a jurisdiction where they have an obligation.
- Sales-tax rates: State, county, city, and special-district rates can differ.
- Sales-tax filing: Businesses must report and remit collected tax on the schedule assigned by each jurisdiction.
- Use tax: Tax owed when taxable goods are bought without sales tax and then used, stored, or consumed in a state. When an online seller doesn't collect sales tax, the buyer may owe use tax directly to their state.
- Exemption records: Resale, nonprofit, and other exempt sales need valid certificates on file to support not collecting tax.
Understanding these components helps businesses manage liability and reduce penalties.
How Does Ecommerce Sales Tax Work?
Ecommerce sales-tax compliance involves collecting and remitting tax on online transactions across state and national boundaries. Sellers need to understand where obligations arise, which products are taxable, and how sourcing rules apply.
History of Ecommerce Sales Tax: South Dakota v. Wayfair
Before Wayfair, the prevailing physical-presence standard generally required a store, warehouse, employee, or other in-state connection. The Supreme Court’s 2018 decision allowed states to impose collection obligations based on economic activity.
South Dakota’s law, which used a $100,000 sales or 200-transaction threshold, became a model for other states. Current thresholds vary, and many states have changed or removed transaction-count tests.
Economic Nexus and Its Importance
Economic nexus is a connection created by a business’s economic activity in a state. A seller can establish it through revenue, transaction count, or another state-specific test without having employees or property there.
Businesses should monitor activity by state, register when required, calculate the right rate, and file by each assigned deadline. Our US sales tax calculator shows the combined rate for any US address.
2025–2026 Changes Affecting Ecommerce Sellers
States continue to update rates, exemptions, taxability rules, and nexus thresholds. Sellers should verify current treatment for products shipped into each state rather than relying on historical guidance.
Some states have removed the 200-transaction prong from their economic-nexus tests, leaving a revenue threshold as the primary trigger. This can simplify tracking for some sellers but does not eliminate the need to monitor sales and state-specific obligations.
Destination-Based vs. Origin-Based Sourcing
Sales tax can use destination-based or origin-based sourcing:
- Destination-based sourcing: The rate is generally based on where the customer receives the product.
- Origin-based sourcing: The rate may be based on the seller’s location.
Confirm which sourcing rule applies to the transaction and jurisdiction. A seller in New York shipping to California may need to use California’s applicable destination rate rather than the seller’s rate.
Most ecommerce transactions use destination-based sourcing; a small number of states apply origin-based rules to some in-state sales. Because local rates follow jurisdiction boundaries, a ZIP code alone may not identify the correct rate, so calculate tax from the full delivery address.
Ecommerce Sales Tax on Amazon or eBay
Marketplace facilitator laws require many platforms, including Amazon and eBay, to collect and remit tax for covered transactions. Sellers may still need to register, file informational returns, and collect tax on direct-site or other uncovered sales. See marketplace facilitator laws by state for each state's threshold and what sellers still owe.
Track marketplace and non-marketplace transactions separately and reconcile reports before filing.
Ecommerce Sales Tax on Shopify
Shopify provides tax-configuration tools but is generally not a marketplace facilitator that assumes a seller’s sales-tax obligations. Merchants must determine where they have nexus, register, configure collection, manage exemptions, and file returns.
Automation tools can help Shopify merchants monitor nexus, apply current rates, classify products, and organise filing data.
Strategies for Efficient Tax Management
- Understand physical and economic nexus obligations.
- Register in required jurisdictions.
- Apply the correct rate for each destination and taxable product.
- Classify products and services accurately.
- Maintain transaction and exemption records.
- File every assigned return, even for periods with no taxable sales; many states require zero-dollar returns.
- Stay current on rate, threshold, and taxability changes.
- Monitor international VAT and GST obligations when expanding globally.
- Automate sales-tax monitoring, calculation, reconciliation, and filing where appropriate.
Final Thoughts
Ecommerce sales tax is complex because rates, nexus, sourcing, exemptions, and filing rules vary by jurisdiction. Kintsugi can help businesses monitor nexus, calculate rates, manage exemptions, and organise filings across sales channels. To compare tools, see our guide to the top ecommerce sales tax software.
Businesses remain responsible for reviewing configuration and meeting their legal obligations. Explore Kintsugi’s sales-tax platform or book a demo to learn more.
