Most non-resident e-commerce sellers believe a dangerous tax myth that could cost them thousands in unexpected US tax liability. James Baker exposes the #1 misconception and explains the real rules around ECI, inventory nexus, and FBA.
The #1 tax myth among non-resident e-commerce sellers is the belief that selling products to US customers automatically creates US tax liability. This misconception has led thousands of international entrepreneurs to either avoid the US market entirely — leaving significant revenue on the table — or to overpay taxes based on incorrect advice from accountants who don't specialize in international taxation.
The reality is far more nuanced. Whether a non-resident e-commerce seller owes US federal income tax depends not on where their customers are located, but on where the income is sourced under the Internal Revenue Code. The sourcing rules for different types of e-commerce income vary significantly, and understanding these distinctions is the key to legitimate tax optimization.
For non-residents, the US taxes only two categories of income: Effectively Connected Income (ECI) — income connected to a US trade or business — and Fixed, Determinable, Annual, or Periodical (FDAP) income from US sources. If your e-commerce income doesn't fall into either category, it's not subject to US federal income tax, regardless of how many US customers you serve.
Here's where the myth becomes partially true — and where many sellers get caught. Amazon FBA (Fulfillment by Amazon) creates a unique tax situation for non-resident sellers because Amazon stores your inventory in US warehouses. Under IRS rules, having inventory stored in the US can create a "fixed place of business" that constitutes a US trade or business.
When a non-resident has a US trade or business, the income effectively connected to that business is taxed as ECI at the same graduated rates that apply to US citizens and residents. For Amazon FBA sellers, this means the profit from sales fulfilled from US warehouses may be subject to US federal income tax.
However, this doesn't mean all Amazon income is taxable. The IRS applies a three-part test to determine whether income is ECI: (1) Is there a US trade or business? (2) Is the income effectively connected to that trade or business? (3) What is the source of the income? For FBA sellers, the first two questions are typically answered "yes," but the tax calculation depends on the specific facts of each case.
The critical distinction is between sellers who use FBA exclusively and those who also fulfill orders from outside the US. If you fulfill some orders from your home country and some through FBA, only the FBA-fulfilled sales may be subject to US tax. Proper allocation of income between US and foreign fulfillment channels can significantly reduce your US tax liability.
For non-resident sellers who operate Shopify stores or other direct e-commerce platforms and fulfill orders from outside the United States, the tax analysis is fundamentally different from Amazon FBA. When you ship products directly from your home country to US customers, you typically do not have a US trade or business — which means your income is not ECI.
The income from these sales is generally classified as foreign-source income under the IRS sourcing rules. The sale of personal property (inventory) by a non-resident is sourced based on where the seller's tax home is located — not where the buyer is located. Since your tax home is outside the US, the income is foreign-sourced and not subject to US federal income tax.
This is the key insight that the myth obscures: you can sell millions of dollars worth of products to US customers through your Shopify store, fulfill orders from your home country, and owe zero US federal income tax. The tax obligation depends on where you perform the business activities, not where your customers are.
Of course, this analysis assumes you're not performing significant business activities in the US. If you travel to the US regularly to manage your business, attend trade shows, or meet with suppliers, you may inadvertently create a US trade or business. The line between occasional business travel and establishing a US presence is fact-specific and should be evaluated with a qualified CPA.
One of the reasons the e-commerce tax myth persists is that many sellers confuse federal income tax with state sales tax. These are completely separate tax obligations with different rules, different thresholds, and different compliance requirements.
Since the Supreme Court's 2018 decision in South Dakota v. Wayfair, states can require out-of-state sellers to collect and remit sales tax if they exceed certain economic nexus thresholds — typically $100,000 in sales or 200 transactions in a state. This applies to non-resident sellers just as it applies to domestic sellers.
However, most non-resident e-commerce sellers benefit from marketplace facilitator laws. In all 50 states that collect sales tax, marketplace facilitators like Amazon, Etsy, and Walmart are required to collect and remit sales tax on behalf of their third-party sellers. This means that if you sell exclusively through these marketplaces, the platform handles your sales tax obligations automatically.
For Shopify sellers and those with their own websites, sales tax compliance is more complex. You may need to register for sales tax permits in states where you exceed economic nexus thresholds and either collect sales tax directly or use a service like TaxJar or Avalara to automate the process. This is a compliance obligation, not an income tax — the sales tax is collected from your customers, not paid from your profits.