Expanding your online business into the U.S. can open huge doors — more customers, better visibility, and a trusted brand image. But there’s a catch that many foreign sellers don’t see coming: U.S. tax nexus.
It sounds technical, but in simple terms, it’s about when your business becomes connected enough to a state that you owe taxes there. And for foreign e-commerce sellers who’ve set up a U.S. company, those connections can happen faster — and more easily — than you think.
Understanding nexus isn’t just about staying compliant. It’s about protecting your profits and avoiding unnecessary filings or penalties that can quietly eat into your growth.
What “Nexus” Means
In U.S. tax language, nexus just means a link strong enough for a state to claim you owe taxes there. It’s just the government’s way of deciding whether your business is active enough in a state to owe taxes there.
There are two main ways that happen:
- Physical Nexus: This one’s pretty straightforward. If you’ve got something real in a state — an office, a warehouse, staff, or even a bit of inventory sitting in storage — that counts as a physical presence.
- Economic Nexus: When your sales into that state hit a certain level, even if you’ve never been there. In most states, that threshold sits around $100,000 in annual sales or 200 transactions.
For online sellers, the second one — economic nexus — is the one that trips people up. You might be sitting halfway across the world, but if your U.S. company sells enough in a state like Texas or Florida, that state expects you to collect and file sales tax.
Why Nexus Catches Foreign Sellers Off Guard
Foreign business owners often think registering a U.S. entity — like an LLC or C-Corp — means they’re automatically compliant. But in reality, the U.S. system is state-based, not just federal.
That means each state where you do business can set its own rules about:
- When you must collect and remit sales tax
- When you need a local business registration
- When income is taxable at the state level
Even if you sell primarily through Amazon or Shopify, the states still care where your customers are. Amazon, for instance, handles marketplace sales tax in most states, but you’re still responsible for reporting your own website’s direct sales.
2025 Update: States Are Getting Stricter
As of 2025, many states have increased audit activity on remote sellers. Some now send automated notices when platforms or payment processors report large in-state sales.
Several states — including California, New York, and Florida — also added data-sharing partnerships to flag unregistered sellers with high transaction volumes.
That means ignoring nexus risks is harder than ever. A small oversight could trigger back-tax bills or registration penalties that eat into your profit margins fast.
How to Avoid Nexus Trouble Before It Starts
1. Map Out Where You Have Presence or Sales
Start with a sales report by state. Include all channels — your own site, Amazon, eBay, Etsy, and any U.S. fulfillment centers.
Look for states where your total yearly sales cross $100,000 or more. Those are your likely nexus triggers.
2. Register in the Right States — Not All of Them
You don’t need to register everywhere, just where you meet nexus thresholds. Over-registering can create unnecessary costs.
Check each state’s Department of Revenue site for current sales limits. A few states like Kansas and Missouri still have different rules in 2025.
3. Use Marketplace Facilitator Rules to Your Advantage
If you sell mainly through Amazon or Walmart Marketplace, they’re already collecting and remitting sales tax for your marketplace orders.
But — and this is key — that doesn’t cover sales from your own Shopify store or direct website. Make sure you separate and track those sales clearly.
4. Keep Track of Fulfillment Centers and Third-Party Warehouses
If your goods sit in U.S. warehouses (like Amazon FBA centers), that’s physical nexus — even if you never visit.
Keep a record of where your inventory is stored. Amazon updates this info in Seller Central, but double-check it quarterly.
5. Automate Sales Tax Collection and Filing
Manually tracking tax rates across states is a recipe for mistakes. It’s much easier to let software handle it.
Tools like Avalara, TaxJar, or Sovos connect directly with platforms such as Shopify, WooCommerce, and BigCommerce.
They figure out the right rate for each state automatically and file your returns on time. It saves hours of back-and-forth and keeps your records consistent — no spreadsheets, no guessing, just clean, accurate filings.
6. Watch for Permanent Establishment (PE) Risks
If your company has staff, contractors, or a dependent agent working in the U.S., you might create a Permanent Establishment under IRS and treaty rules — leading to federal income tax exposure.
If you’re unsure, talk to a tax advisor who understands cross-border setups. Filing Express can connect you with professionals who handle BOI, EIN, and U.S. tax filing for foreign-owned companies.
Real Example: When Nexus Surprises a Seller
A U.K.-based e-commerce brand used a Delaware LLC to sell eco-friendly home goods online. Most sales came through Amazon, so they assumed tax was handled.
However, they also shipped directly to customers from a New Jersey warehouse. That warehouse created a physical nexus, triggering back-filing obligations in New Jersey and nearby states.
After getting caught during a sales tax audit, the company had to pay two years of back taxes and penalties — even though total sales were modest.
The fix? They switched to using Amazon’s own fulfillment network and properly registered in key states.
What to Do if You Already Have Nexus
If you suspect you’ve already triggered nexus, don’t ignore it. Most states allow voluntary disclosure agreements (VDAs) — a way to come forward, register, and pay limited back taxes without heavy penalties.
The sooner you act, the easier it is to limit liability and get back into good standing.
Final Thoughts
Nexus rules sound complicated — and they are — but staying compliant doesn’t have to be painful.
Start by knowing where you sell, automate your filings, and keep good records of inventory and fulfillment.
For foreign e-commerce founders, it’s all about control. The more you track early, the fewer surprises you’ll face later.
And when in doubt, get expert help — the right advice upfront costs far less than fixing mistakes later.
