For Amazon FBA Sellers

Sales Tax for Amazon FBA Sellers: Monitor Your Nexus

Amazon collects marketplace tax. But your FBA inventory creates physical nexus that affects your other sales channels.

The FBA trap: If Amazon stores your inventory in California, you have physical nexus in California — which means sales through your Shopify store, your website, or direct to California customers may require you to collect and remit sales tax, regardless of whether Amazon is handling your Amazon orders.

Start monitoring your nexus

Not tax advice. NexusFlag tracks published state nexus rules — consult a CPA for guidance on FBA-specific obligations.

The FBA nexus trap, explained simply

Most FBA sellers assume "Amazon handles tax for me." That's only half true.

1

Amazon stores your FBA inventory across 30+ states

Amazon decides where your inventory goes. You often have no control over which fulfillment centers hold your products.

2

That inventory creates physical nexus in each state

Having inventory in a state — even if you didn't choose to put it there — is generally considered physical nexus under most state tax laws.

3

Amazon collects tax on Amazon sales — but not your other channels

Marketplace facilitator laws mean Amazon handles tax collection for Amazon.com orders. Your Shopify store, website, or wholesale orders in those same states? That's your responsibility.

4

You may owe back taxes on years of non-Amazon sales

If you've had FBA inventory in California for three years and sold directly to California customers without collecting tax, you may have a back-tax exposure — even if Amazon was collecting on your Amazon orders.

Key fact: Amazon currently operates fulfillment centers in more than 30 states. If you sell via FBA, you likely have physical nexus in more states than you realize — and that nexus applies to every channel you sell through, not just Amazon.

How NexusFlag monitors both exposures

FBA sellers have two distinct nexus problems. NexusFlag tracks both.

🏭

Physical nexus from FBA inventory

Log the states where Amazon holds your FBA inventory. NexusFlag tracks your physical presence nexus separately from your economic nexus exposure.

📈

Economic nexus on non-marketplace sales

Your trailing-12-month revenue from non-Amazon channels is measured against each state's economic nexus threshold. Separate tracking from marketplace sales.

🔔

Threshold alerts as you approach limits

Get notified at 50%, 80%, and 100% of each state's economic threshold for your direct sales. Physical nexus states are flagged immediately.

📅

Registration deadline tracking

Once you've established nexus — physical or economic — most states require registration within a defined window. NexusFlag tracks those deadlines per state.

The real risk: back taxes on direct sales

State auditors aren't focused on your Amazon orders — Amazon files reports with states. They're focused on whether you've been collecting on your direct sales in states where you have nexus.

The average sales tax audit results in approximately $12,000 in back taxes, interest, and penalties. Most FBA sellers with a Shopify store or website have direct-channel exposure in multiple states — and most don't know it.

See your exposure now

Amazon seller questions

Amazon collects sales tax for me. Why do I still need to worry?

Amazon collects and remits sales tax on marketplace sales as a marketplace facilitator. But physical nexus created by your FBA inventory in Amazon's warehouses applies to ALL of your sales channels — your website, Shopify store, Etsy shop, wholesale, and direct. If you have FBA inventory in a state, you almost certainly have physical nexus there, which means your non-Amazon sales in that state may require you to collect and remit sales tax.

What is FBA physical nexus?

Physical nexus is created when you have inventory, employees, or other physical presence in a state. Because Amazon stores your FBA inventory in fulfillment centers distributed across many states, that inventory creates physical nexus in each of those states — regardless of your sales volume. Physical nexus thresholds have no minimum; simply having inventory in a state may be enough.

Which states have Amazon fulfillment centers?

Amazon operates fulfillment centers in over 30 states. The exact states where your inventory is stored vary based on Amazon's distribution decisions, which change over time. NexusFlag lets you log the states where you know your FBA inventory is stored, then tracks physical nexus alongside your economic nexus exposure.

Do I need to file sales tax returns in every state where Amazon has my inventory?

Potentially, for sales from non-Amazon channels. This is a complex area where professional advice matters. NexusFlag helps you identify the exposure — a CPA or sales tax attorney should advise you on your registration and filing obligations.

Find out where you have nexus

Enter your FBA states and your non-Amazon revenue — get a clear picture of your exposure in minutes.

Not tax advice. NexusFlag monitors published state nexus rules — consult a CPA for guidance on your FBA-specific obligations.