Economic Nexus Explained: The Post-Wayfair Sales Tax Landscape
The 2018 Wayfair decision fundamentally changed sales tax obligations for businesses selling across state lines. Here is what economic nexus means for your business.
Before 2018, businesses only needed to collect sales tax in states where they had a physical presence—an office, warehouse, or employees. The Supreme Court's landmark South Dakota v. Wayfair decision changed everything. Now, states can require out-of-state sellers to collect sales tax based purely on their economic activity in that state.
This guide explains what economic nexus is, how to determine if you have it, and what steps to take when thresholds are met. For a broader view of all nexus types and compliance strategies, see our Complete Guide to Sales Tax Nexus.
Compliance Is Not Optional
States actively pursue out-of-state sellers who fail to collect sales tax. Penalties include back taxes, interest, and fines. Many states share data with each other, making it increasingly difficult to fly under the radar.
The Wayfair Decision and Its Implications
For decades, the 1992 Quill Corp. v. North Dakota decision established that businesses needed physical presence in a state before that state could require sales tax collection. This created a significant advantage for online retailers who could sell nationwide without collecting sales tax in most states.
What Changed in 2018
In South Dakota v. Wayfair, Inc., the Supreme Court overturned Quill, ruling that physical presence was not required for a state to impose sales tax collection obligations. The Court upheld South Dakota's law that required out-of-state sellers to collect sales tax if they had:
South Dakota's Original Thresholds
Why the Court Allowed This
The Court found South Dakota's law constitutional because it included several protections for small sellers and interstate commerce:
- Safe harbor for small sellers: The thresholds ensured only businesses with substantial economic presence were affected
- No retroactive application: The law only applied to sales made after the effective date, not historical transactions
- Streamlined Sales Tax membership: South Dakota is part of the Streamlined Sales and Use Tax Agreement, which simplifies multi-state compliance
- Free compliance software: The state provides access to software that calculates correct rates and filing requirements
The Domino Effect
Within months of the Wayfair decision, virtually every state with a sales tax enacted economic nexus laws. Today, all 45 states that impose sales tax (plus Washington D.C.) have economic nexus provisions, though thresholds and rules vary.
Economic Nexus Thresholds by State
While South Dakota's $100,000/200 transaction model became the template, states have adopted varying thresholds. Understanding these differences is critical for compliance planning. For detailed state-by-state thresholds, see our State-by-State Nexus Threshold Guide.
Common Threshold Patterns
| Threshold Type | Description | Example States |
|---|---|---|
| $100K OR 200 transactions | Original Wayfair model; either threshold triggers nexus | South Dakota, Indiana, Nebraska |
| $100K only (no transaction count) | Revenue-only threshold; many states dropped transaction test | California, Texas, Florida, New York |
| $500K threshold | Higher threshold in some states | Texas (for certain sellers), California (originally) |
| Lower thresholds | Some states set thresholds below $100K | Pennsylvania ($100K), some have 100 transaction thresholds |
Important Threshold Considerations
Measurement Period
States may measure against the prior calendar year, current calendar year, or trailing 12 months. Some use "current or prior year" language, meaning you have nexus if you exceeded thresholds in either period.
Gross vs. Taxable Sales
Some states count all sales into the state; others only count taxable sales. If you sell products that are exempt in a particular state, this distinction matters significantly for threshold calculations.
Wholesale vs. Retail
Some states exclude wholesale sales from threshold calculations. Others count all B2B and B2C transactions equally. Review each state's specific rules based on your business model.
Marketplace Sales
Sales made through marketplace facilitators (Amazon, eBay, Etsy) may or may not count toward your threshold, depending on state rules. More on this below.
Transaction Count vs. Revenue Triggers
The original Wayfair model included both revenue AND transaction thresholds. However, the trend has been moving away from transaction counts. Understanding why helps you plan your compliance strategy.
Why Transaction Counts Existed
The 200-transaction threshold was designed to capture businesses with significant market presence regardless of individual order values. A company selling 300 $10 items into a state has meaningful economic presence even though total sales are only $3,000.
The Shift Away from Transaction Counts
Many states have eliminated their transaction count thresholds, including:
- California: Dropped the 200-transaction test, now $500,000 revenue only
- Texas: $500,000 revenue threshold, no transaction count
- New York: $500,000 AND 100 transactions (both required)
- Florida: $100,000 revenue only, no transaction count
Strategic Implication
If your business has high transaction volumes but low per-order values (such as digital goods or small physical items), the elimination of transaction thresholds may reduce your compliance burden. However, you still need to track sales carefully as thresholds can change and vary by state.
Tracking Both Metrics
Even if some states no longer use transaction counts, we recommend tracking both revenue and transaction volume by state. This ensures you:
- Remain compliant in states that still use transaction thresholds
- Can quickly adapt if states reinstate transaction-based rules
- Have complete data for nexus studies and audit defense
- Can forecast when you might exceed thresholds in new states
Marketplace Facilitator Rules
One of the most significant developments since Wayfair is the rise of marketplace facilitator laws. These laws shift sales tax collection responsibility from individual sellers to the platforms they sell through.
What Is a Marketplace Facilitator?
A marketplace facilitator is a platform that:
- Lists products from third-party sellers
- Facilitates sales between buyers and sellers
- Processes payments on behalf of sellers
Common examples include Amazon, eBay, Etsy, Walmart Marketplace, and Shopify (when payment processing is used).
How These Laws Work
Marketplace Responsibility
In most states with marketplace facilitator laws, the platform (like Amazon) is required to collect and remit sales tax on behalf of third-party sellers. The seller is relieved of this obligation for those specific sales.
Seller Still Has Obligations
You may still have nexus obligations for direct sales (through your own website), sales in states without marketplace facilitator laws, or if the marketplace does not collect tax in certain jurisdictions.
Threshold Calculations and Marketplaces
Whether marketplace sales count toward your economic nexus threshold varies by state:
States That Exclude Marketplace Sales
Some states do not count sales made through marketplace facilitators toward your nexus threshold. If all your sales are through Amazon, you may not have independent nexus obligations.
States That Include Marketplace Sales
Other states count all sales into the state, regardless of channel. Even if Amazon collects tax, your total sales volume creates nexus obligations that require registration and potentially reporting.
Do Not Assume You Are Covered
Just because a marketplace collects sales tax does not mean you have zero obligations. You may still need to register, file zero-dollar returns, or collect tax on direct sales. Review each state's specific requirements.
When Economic Nexus Is Triggered
Understanding exactly when nexus is triggered helps you plan registration and compliance timing. The answer varies by state, but here are the common patterns.
Triggering Events
Threshold Exceeded
You meet or exceed the state's revenue and/or transaction threshold. This is the triggering event that creates nexus.
Registration Required
Most states require registration within 30-60 days of exceeding the threshold. Some require registration before making the next sale after threshold is met.
Collection Begins
Once registered, you must begin collecting tax on taxable sales. The effective date varies—some states require collection starting with the next sale, others on the first of the following month.
Common Timing Rules
| Timing Rule | Description | Example |
|---|---|---|
| Immediate | Collection required on the sale that exceeds threshold | Exceed $100K on Oct 15; collect starting Oct 15 |
| First of next month | Collection begins on the first day of the following month | Exceed $100K on Oct 15; collect starting Nov 1 |
| Calendar year start | Prior year threshold creates nexus for entire following year | Exceed $100K in 2025; collect for all of 2026 |
When Nexus Ends
If your sales drop below the threshold, you may eventually no longer have nexus. However, this does not happen immediately:
- Most states: You must fall below the threshold for a full measurement period (usually a calendar year) before nexus ends
- Registration remains: Even after nexus ends, you may need to formally close your account or continue filing zero returns
- Prior obligations remain: Any tax owed for periods when you had nexus is still due regardless of current status
Proactive Tracking Is Essential
We recommend setting internal alerts at 75% and 90% of threshold levels in each state. This gives you time to prepare for registration rather than scrambling after the fact. Automated sales tax software can handle this tracking for you.
Steps When You Trigger Economic Nexus
When you exceed a state's economic nexus threshold, here is the typical process:
Verify Threshold Exceeded
Confirm you have actually exceeded the threshold based on the state's specific rules (gross vs. taxable sales, measurement period, etc.).
Register for a Sales Tax Permit
Apply for a sales tax permit in the state. Many states offer online registration. The Streamlined Sales Tax Registration System allows registration in multiple member states at once.
Configure Your Systems
Update your billing and e-commerce systems to calculate and collect the correct tax rates. Remember that rates vary by jurisdiction—state, county, city, and special districts.
Begin Collecting Tax
Start collecting sales tax from customers in that state according to the state's required timeline (immediate, first of month, etc.).
File Returns and Remit Tax
File sales tax returns according to the assigned frequency (monthly, quarterly, or annually based on your volume) and remit the collected tax.
Need Help Managing Sales Tax Compliance?
Eagle Rock CFO helps growing businesses navigate sales tax nexus, implement compliant processes, and select the right tools for multi-state compliance. Our outsourced finance team handles the complexity so you can focus on growth.
Schedule a Consultation