Wayfair and economic nexus
Since South Dakota v. Wayfair, physical presence is no longer required in most states. Remote sellers generally must register once they cross the revenue or transaction threshold set by a state.
Verified April 2026
eCommerce Sales Tax Guide
Marketplace rules, economic nexus, digital goods taxability, and filing workflow guidance for multi-state online sellers.
Multi-state compliance
What online sellers need to track
The post-Wayfair sales tax environment requires ongoing monitoring of nexus thresholds, marketplace collection rules, taxability updates, filing schedules, and state-specific digital goods treatment.
Economic nexus
Revenue or transaction thresholds can trigger registration even without physical presence.
Marketplace facilitators
Amazon, Etsy, Walmart, and other platforms may collect tax, but filing duties can still remain.
Digital goods
SaaS, downloads, subscriptions, and streaming can be taxable or exempt depending on the state.
Filing cadence
Monthly, quarterly, and annual schedules vary by state and sales volume.
Data-backed guide
Taxability and contact coverage
States
24
Taxability updates
590
State contacts
52
Marketplace facilitator rules
Many states require marketplaces to collect sales tax for third-party sellers. Even when the marketplace remits the tax, you may still need a permit, a filing account, or a zero-dollar return.
Origin vs destination sourcing
Origin-based states use the seller location to determine the rate. Destination-based states use the customer shipping address. A national seller often has to apply both models depending on the state.
Digital goods and SaaS
Digital goods rules remain one of the biggest compliance gaps for ecommerce sellers. Downloads, software access, maintenance, and data processing can each be treated differently across states.
Operating checklist
A practical workflow for online sellers
01
Track state sales
Monitor gross revenue and transaction count by destination state.
02
Register fast
Apply for permits once thresholds are crossed or before marketplace-only filing is required.
03
Map product taxability
Separate physical goods, digital goods, SaaS, food, and exempt sales.
04
File and archive
Store exemption certificates, filing confirmations, and state notices for audit readiness.