Economic Nexus Explained

In South Dakota v. Wayfair (2018), the Supreme Court overturned the physical presence requirement that had governed sales tax for over 50 years. The Court upheld South Dakota economic nexus law, establishing that states can require out-of-state sellers to collect tax based solely on economic activity within the state. This decision opened the door for all 45 sales tax states (plus D.C.) to enact economic nexus provisions.

Before Wayfair, the physical presence rule dominated sales tax since the 1960s. Under that rule, a business only had sales tax obligations in states where it had some physical presence—an office, employees, warehouse, or inventory. This meant online sellers could sell to customers nationwide without collecting tax, creating an advantage over brick-and-mortar retailers who had to collect tax on every sale.

Wayfair changed this calculus dramatically. The Court found that the physical presence rule was outdated in the modern economy, where businesses can sell to customers in any state without traditional physical presence. The decision recognized that economic activity in a state—significant sales to customers in that state—creates a sufficient connection to justify requiring tax collection.

The practical impact was immediate and far-reaching. Within months of the decision, most sales tax states enacted economic nexus laws. Today, virtually every state with a sales tax has some form of economic nexus provision. For businesses, this means that selling to customers in a state—even without any physical presence there—can trigger sales tax registration and collection obligations.

The decision also validated states' authority to set their own thresholds for when economic activity is sufficient to create nexus. While states must show the thresholds don't unduly burden interstate commerce, they've adopted a range of thresholds based on sales revenue, transaction counts, or both.

Economic nexus thresholds define the level of economic activity that triggers tax obligations. States use various combinations of revenue and transaction thresholds, creating a complex compliance landscape.

Revenue thresholds look at total sales into a state. Common revenue thresholds range from $100,000 to $500,000 annually. If your sales to customers in a state exceed this amount, you have economic nexus and must register and collect tax. Revenue thresholds may be cumulative (all sales regardless of taxability) or taxable sales only, depending on the state.

Transaction thresholds count the number of separate sales into a state. Common transaction thresholds range from 100 to 200 transactions annually. Each state defines what counts as a transaction—some count every invoice, others count individual line items. Some states have both revenue and transaction thresholds and use an OR structure—you trigger nexus if you exceed either.

Most states adopted the South Dakota model of $100,000 in sales OR 200 transactions. This became the de facto standard and was viewed as striking a balance between capturing significant sellers and not burdening small businesses. States with higher thresholds, like California and New York at $500,000, target larger sellers while providing more flexibility for smaller businesses.

Some smaller states adopted lower thresholds that attracted attention and legal challenges. While some were struck down, others were upheld. States like Minnesota ($100,000) and Wisconsin ($100,000) have thresholds similar to larger states. Smaller thresholds in some states may affect businesses selling into those specific states even if they don't exceed larger states' thresholds.

Threshold amounts can change. States periodically revise thresholds, sometimes to address inflation or changing economic conditions. Stay current on threshold changes in states where you sell, particularly states where your sales are approaching threshold levels.

While economic nexus has become the dominant trigger for sales tax obligations, understanding other types of nexus ensures complete compliance. Many businesses have nexus through multiple factors, and all nexus types should be tracked.

Physical presence nexus existed before Wayfair and continues to create obligations. Having employees, offices, warehouses, or inventory in a state triggers nexus regardless of sales volume. Physical presence is immediate—you have nexus as soon as the physical presence is established. For growing businesses, adding employees in new states or opening new locations creates immediate nexus.

Affiliate nexus creates obligations through relationships with other businesses. If an affiliated company has physical presence or economic nexus in a state, your company may also have nexus through that affiliation. Affiliate relationships can include parent companies, subsidiaries, or commonly controlled businesses. The specific rules vary by state.

Marketplace facilitator nexus has become increasingly important. Under marketplace facilitator laws, large marketplaces like Amazon, eBay, or Walmart must collect tax on sales made through their platform. This shifts the collection burden from sellers to marketplaces for those sales. However, sellers remain responsible for tax on direct sales outside marketplace channels.

Click-through nexus involves relationships with referrers who generate sales into a state. If you pay commissions to someone in a state for referring customers, some states consider that click-through nexus. The rules vary significantly—some states have eliminated click-through provisions following Wayfair, while others retain them.

Dropship nexus can create obligations through your suppliers. If you sell products shipped from a warehouse in a state, you may have nexus through that dropship relationship. The specific rules depend on whether you or your supplier have nexus in the state and whether the state views dropship arrangements as creating taxable nexus.

Understanding all nexus types is essential because different triggers may have different requirements. Physical presence, for example, creates immediate nexus without any threshold—you must register and begin collecting immediately upon establishing presence.

Assessing your economic nexus position requires understanding where your customers are located and how your sales compare to each state's thresholds. A systematic approach ensures you identify all states where you have or are approaching nexus.

Start by analyzing your sales data by state. Your sales system should provide reports showing sales by destination state or customer location. If you don't have this data, work with your accounting team or platform to generate reports. Accurate state-level sales data is the foundation of nexus analysis.

Calculate your sales by state for the current year and look-back periods. Many states use a rolling 12-month look-back to determine if you've exceeded thresholds. Some use a calendar year, while others use fiscal year basis. Understanding each state's approach ensures you're comparing correctly.

Map your sales against each state's thresholds. For states where you've exceeded thresholds, you have nexus. For states where you're approaching thresholds, monitor closely. For states where you're well below thresholds, document your position.

Track projections for the remainder of the year. Nexus isn't just about what you've already sold—it's about what you're likely to sell. If you're on pace to exceed thresholds in a state, proactive registration before the threshold breach demonstrates good faith and can limit penalty exposure.

Document your analysis. Good documentation serves two purposes. First, it ensures you've considered all relevant factors. Second, if you're ever audited, documentation showing your analysis demonstrates good faith compliance efforts and can affect penalty assessments.

Repeat the analysis regularly—quarterly at minimum. Your sales patterns change, new states adopt economic nexus laws, and thresholds change. Regular analysis ensures you stay current on your obligations.

Once you determine you've established economic nexus in a state, you have obligations that must be addressed promptly. Understanding what to do helps you comply efficiently and avoid penalties.

Register for a sales tax permit in the state. Registration is required before you can legally collect tax. Most states allow online registration through their department of revenue. The process typically takes a few days to a few weeks, so begin immediately upon determining nexus exists.

Configure your systems to collect tax from customers in that state. This may involve updating your e-commerce platform, point of sale system, or billing software. Ensure the correct rate is applied based on customer location and product taxability.

Begin collecting tax on sales to customers in that state from the date nexus is established. Some states allow collection to begin immediately upon registration; others specify a specific effective date. Follow the state's requirements.

Set up filing procedures for the new state. Determine your filing frequency based on the state's assignment or your expected tax liability. Mark filing deadlines on your calendar and ensure returns are filed on time.

Maintain records of your nexus determination and the date you began collecting. Documentation is essential in case of audit. Show the analysis that led to your determination and the date you registered and began collecting.

The good news is that states generally provide a reasonable period to come into compliance after first exceeding thresholds. However, the exact period varies by state, and penalties can apply for late registration. Address nexus determinations promptly.

Ongoing nexus management helps you stay compliant as your business evolves. Without systematic tracking, it's easy to lose track of which states require registration and when thresholds are approaching.

Implement sales tracking by state. Your accounting or sales systems should provide state-level reporting. Regular review of this data keeps you informed about your position in each state.

Monitor threshold proximity. For states where you're approaching thresholds, track progress throughout the year. Set internal alerts for when you're at 75% or 90% of threshold levels to give yourself time to register before breach.

Consider nexus tracking tools. Many sales tax automation platforms include nexus monitoring that tracks your sales and alerts you when thresholds approach. This automation reduces the burden of manual tracking and ensures nothing falls through the cracks.

Plan for expansion intentionally. If you're planning to enter new markets or expect significant growth in certain states, account for nexus implications in your planning. Registration before threshold breach is preferable to scrambling after.

Review your determination analysis annually at minimum. Business conditions change, states change their laws, and thresholds change. Annual review ensures your analysis remains current and your compliance position is accurate.