Amazon FBA Sales Tax Nexus: What Every Seller Must Know

So, you launched your Amazon FBA business, sales are rolling in, and life feels good. But here is the question that could quietly derail all of that momentum: do you actually know how many states consider you a taxpayer right now? If you are like most FBA sellers, the answer is probably “not as many as I actually am.” That is exactly where the concept of Amazon FBA sales tax nexus becomes critically important, and where ignoring it can cost you far more than you ever expected.

Let’s break this down clearly, practically, and without the legal jargon that makes most sellers’ eyes glaze over.

What Is Sales Tax Nexus and Why Does It Matter for FBA Sellers?

The Simple Definition of Nexus

Think of sales tax nexus as a legal handshake between your business and a state. Nexus refers to the connection between a business and a taxing jurisdiction that creates an obligation to collect and remit sales tax. Once that handshake happens, the state has the authority to require you to register, collect tax from customers, and file returns. Refuse to comply? You risk back taxes, penalties, and interest that pile up fast.

The word “nexus” comes from Latin, meaning “bond” or “connection.” It is a fitting name. Because once that bond is established, you are legally connected to that state’s tax system whether you realize it or not.

Why FBA Makes Nexus Far More Complicated

Here is where it gets tricky for FBA sellers specifically. With the rise of Amazon’s Fulfillment by Amazon (FBA) program, a service where Amazon stores, packages, and ships products on behalf of sellers, sellers can trigger nexus in states they were not even aware they were connected to.

In other words, you could be sitting in your home office in Texas, yet simultaneously have legal tax obligations in California, Illinois, Michigan, and six other states — all because Amazon decided to redistribute your inventory across its nationwide warehouse network. That is a staggering reality for sellers who thought they were only doing business in one place.

The Two Types of Amazon FBA Sales Tax Nexus

Understanding Amazon FBA sales tax nexus starts with recognizing that nexus comes in two distinct flavors. Each one works differently, and both can apply to you at the same time.

Physical Nexus — Your Inventory Is the Trigger

Physical nexus includes any business activities that involve you or your business having a physical presence in a state, including storing inventory in Amazon FBA warehouses or other third-party fulfillment centers.

The key insight here is this: you do not have to set foot in a state for physical nexus to apply. Your products sitting on an Amazon warehouse shelf are enough. Furthermore, company-owned inventory in a third-party warehouse is considered physical presence, so Amazon FBA sellers must monitor their sales to track where Amazon is sending their inventory.

Physical nexus has no dollar threshold. The moment your goods arrive in a state’s fulfillment center, the connection is made. Period.

Economic Nexus — Your Sales Volume Is the Trigger

Even if Amazon never stores your inventory in a particular state, you can still develop nexus there through sheer sales volume. Economic nexus is based on a seller’s economic activity in a state regardless of physical presence, with each state setting its own thresholds typically based on transaction volume or sales revenue.

For most states, the common threshold is $100,000 in annual sales or 200 transactions into that state. However, some states diverge significantly:

• California and Texas set their threshold at $500,000 in annual sales
• New York requires both $500,000 in sales and more than 100 transactions, making it uniquely strict among U.S. states
• Illinois triggers nexus at $100,000 in sales OR 200 transactions

Why does this variation matter? Because a blanket assumption that “I haven’t hit $100,000 anywhere” may be dangerously wrong once you account for each state’s specific rules.

How Amazon’s Fulfillment Network Silently Creates Nexus

Amazon Moves Your Inventory Without Asking You

This is the part that truly surprises most sellers. You send one shipment to Amazon, and Amazon’s logistics algorithm may redistribute those products across warehouses in a dozen states to optimize delivery speeds for customers. Once you send a shipment to Amazon, it gets distributed to nearly every state, and since there is currently no seller control over this, it is best to register in states that consider physical nexus to have been reached from the outset.

Here is a real-world analogy: imagine hiring a moving company to store your furniture in one warehouse, only to find they quietly moved portions of it to a dozen cities across the country. Now you legally “own property” in all of those locations. That is precisely what FBA inventory placement does to your tax footprint.

Importantly, a Washington State appellate court found that two sellers were responsible for sales tax on sales made through Amazon’s FBA program, noting that the contract between merchants and Amazon directly stated that use of Amazon fulfillment centers could create tax nexus, and that ignorance of the tax implications was not an acceptable defense.

How to Find Out Where Your Inventory Is Stored

Fortunately, you can investigate your own nexus footprint. You can download a list of fulfillment centers storing your inventory in your FBA account and find the column labeled “Fulfillment-Center-ID,” which lists all the fulfillment centers in the country where your products have been stored, identified by airport codes.

For example, seeing “PHX3” means a Phoenix-area center is holding your inventory, which means you likely have nexus in Arizona. This report is your starting point, but interpreting it correctly and acting on it is where professional guidance becomes invaluable.

Does Amazon Handle Your Sales Tax So You Don’t Have To?

What Marketplace Facilitator Laws Actually Cover

Here is the good news: Amazon is a marketplace facilitator, and that designation carries real benefits. Most states now have Marketplace Facilitator Laws, and if you sell through a large platform, that platform is often legally required to collect and remit sales tax on your behalf.

As of today, all 45 states with a state sales tax have marketplace facilitator laws. So for your Amazon sales specifically, Amazon calculates, collects, and remits the tax directly to each state. That does significantly reduce your day-to-day burden.

What Amazon Does NOT Handle for You

However, do not mistake Amazon’s collection role for total protection. This is one of the most common and costly misunderstandings in the FBA world. While Amazon collects and remits tax under marketplace facilitator laws, you as the seller are still responsible for registering for sales tax permits in certain states.

Additionally, you are still responsible for ensuring that you are properly registered for sales tax in states where you have nexus and filing your returns, even if those returns are zero.

So even if your Amazon sales generate no direct remittance obligation for you, many states still require you to:

• Register for a sales tax permit
• File periodic returns (even $0 returns)
• Track and report marketplace-facilitated sales
• Handle compliance for any off-Amazon channels separately

If you also sell on Shopify, your own website, eBay, or via wholesale invoices, Amazon collects nothing for those channels. You carry that responsibility entirely.

State-by-State Differences You Cannot Ignore

High-Stakes States for FBA Sellers

One of the most dangerous assumptions in Amazon FBA sales tax nexus compliance is thinking all states play by the same rules. They absolutely do not. Here is a snapshot of states FBA sellers should watch especially carefully:

• California: California requires out-of-state sellers to collect sales tax if they made more than $500,000 in annual sales the previous year, and California has a deal with Amazon to obtain seller information, meaning sellers who start in 2025 may receive an enforcement letter around 2029.nCalifornia also imposes a minimum $800 annual franchise tax on businesses considered “doing business” in the state.
• New York: If Amazon stores your FBA inventory in a New York warehouse, you have physical nexus the moment your goods arrive, regardless of how much you earn or how many transactions you complete, because Amazon’s inventory placement algorithm moves stock automatically between warehouses.
• Pennsylvania: Notably more permissive than most. A court ruling in the Online Merchants Guild case clarified that inventory in an FBA warehouse does not necessarily create physical nexus for out-of-state sellers who conduct all sales through Amazon in Pennsylvania.
• Washington: Beyond sales tax, Washington imposes a Business & Occupation (B&O) tax based on gross receipts, meaning even marketplace sellers must register and file separately.

The takeaway? You cannot apply one set of rules across fifty states. Every state is its own compliance puzzle.

Common Mistakes FBA Sellers Make With Nexus

Even experienced sellers stumble repeatedly over the same pitfalls. Watch out for these:

1. Assuming Amazon registration equals state registration. Amazon handles tax collection for marketplace sales. It does not register you with state revenue departments.
2. Ignoring physical nexus because sales are low. Physical nexus has no threshold. Fifty dollars of inventory in a California warehouse creates physical nexus in California.
3. Forgetting off-Amazon channels. Launching a Shopify store while assuming your Amazon compliance covers everything is a recipe for an audit.
4. Failing to file zero returns. Many sellers with nexus skip filing because Amazon remits the tax. Several states still require you to file even when the return amount is zero.
5. Not tracking nexus start dates. Most states consider nexus established as soon as you engage in nexus-creating activities including storing inventory, so the start date of your FBA inventory in each state matters significantly for back-tax calculations.

Why Technology Alone Is Not Enough — You Need a Human Expert

Sales tax automation tools are genuinely helpful. Platforms like TaxJar, Avalara, and others can track thresholds, automate filings, and flag potential issues. However, no software can replace the judgment of an experienced sales tax professional when complexity arises.

Consider this: software reads the data you feed it. It does not know that Amazon quietly moved your inventory into a new state last quarter. It does not negotiate with state auditors. It does not identify opportunities for a Voluntary Disclosure Agreement that could dramatically reduce your back-tax exposure. And it certainly does not pick up the phone and talk to a state revenue department on your behalf.

As our article on What Amazon Isn’t Telling You About Your Sales Tax Liability shows, there are layers of FBA compliance risk that sellers discover only after the fact. Similarly, our piece on Inventory Management Sales Tax: 3 Deadly Errors to Avoid outlines how inventory-related decisions directly create tax exposure that software often misses entirely.

Technology handles the repetitive. Humans handle the consequential. When your business is at stake, you want both.

Conclusion

Amazon FBA sales tax nexus is not a single checkbox on a compliance list. It is a web of physical and economic connections across dozens of states, each with its own rules, thresholds, registration deadlines, and filing requirements. Your inventory is traveling across the country right now, silently creating obligations you may not even know exist. And while Amazon collects tax on your marketplace sales, the registration, filing, and multi-channel compliance responsibilities remain firmly on your shoulders.

The smartest move you can make today is to get a clear picture of where your nexus actually stands before a state sends you a notice. At My Sales Tax Firm, we offer a free consultation to help FBA sellers understand their exact exposure, where to register, and how to stay fully compliant as their business grows. Reach out today and let a real human expert review your situation with you.