Sales tax nexus is the connection between a business and a state that allows the state to require sales tax collection and remittance. For online businesses, nexus was traditionally based on physical presence, but economic activity now creates obligations even when a seller has no in-state location.
The 2018 South Dakota v. Wayfair decision changed the framework by allowing states to impose collection obligations based on sales revenue or transaction thresholds. This affects ecommerce sellers, digital service providers, and businesses operating across multiple jurisdictions.
Physical versus economic nexus
Physical nexus
Physical nexus can arise from a store, office, warehouse, employee, contractor, inventory, or other tangible connection in a state.
Economic nexus
Economic nexus applies when a business exceeds a state’s sales or transaction threshold. Thresholds vary, and several states have changed or removed their transaction-count tests, so sellers should review current state rules.
A business can have physical nexus, economic nexus, both, or neither in a given state.
Why nexus matters
Nexus determines where a business may need to:
- register for a sales tax permit;
- collect tax from customers;
- file returns;
- remit collected tax; and
- maintain supporting records.
Missing an obligation can lead to penalties, audits, back taxes, and reputational harm. Understanding the footprint can also help a business plan expansion and supply-chain decisions.
Marketplace facilitators
Marketplace facilitators such as Amazon, Etsy, and eBay often collect and remit tax on eligible marketplace transactions. This may simplify a seller’s obligations, but it does not eliminate the need to monitor overall activity.
Sellers may still need permits, informational returns, and collection for direct website or point-of-sale transactions. Marketplace and direct sales should be reconciled separately so the business understands what was collected by the platform and what remains its responsibility.
Steps to manage nexus
Map the nexus footprint
Document physical connections, sales by destination, transaction counts, inventory locations, employees, contractors, and marketplace activity.
Register where required
Apply for a sales tax permit before collecting in a state where registration is required. Each state has its own process, fees, forms, and filing calendar.
Configure accurate collection
Use current state and local rates, product taxability, sourcing rules, and valid exemption certificates. Address-level calculation is important when local rates differ.
Automate filing
Aggregate transactions by jurisdiction, prepare returns, remit payments, and retain filing confirmations. Automation can reduce manual reconciliation and deadline risk.
Review policy changes
Nexus thresholds and marketplace rules change. Review state guidance regularly and revisit the analysis when adding products, channels, employees, inventory, or customers.
How Kintsugi helps
Kintsugi monitors economic nexus thresholds, identifies where obligations exist or are approaching, tracks the dates nexus is established, and connects transaction data to calculation and filing workflows.
A centralized view of nexus helps online businesses register and collect on time while reducing the chance that a growing sales footprint becomes an unexpected liability.
