Storing goods in a warehouse or fulfillment center in another state creates sales tax nexus there, and it does so the moment your inventory arrives. Every state that collects sales tax treats in-state inventory as a physical connection strong enough to require you to register, collect tax on sales into that state, and file returns. You don’t need an office, employees, or even a customer there. One unit of product on one shelf is enough.
The same event usually creates a state income tax filing obligation as well. For sellers who use third-party logistics providers that move stock between distribution centers, this single rule can generate obligations in a dozen or more states without any decision on your part.
Why Stored Inventory Triggers Nexus
Physical nexus is the original basis on which a state can require an out-of-state business to collect its sales tax. Owning tangible property inside a state’s borders, including merchandise sitting on a warehouse shelf, establishes that connection. The reasoning states rely on is straightforward: your goods benefit from local roads, fire protection, and courts, so you’re expected to participate in the tax structure.
This applies whether you own the warehouse or rent a few pallets of space from a logistics company. All states with a sales tax recognize inventory storage, including storage at third-party warehouses, as a physical nexus trigger.
How Third-Party Fulfillment Multiplies Your Footprint
This is where most sellers get blindsided. Programs like Fulfillment by Amazon and other third-party logistics networks routinely move inventory between distribution centers to shorten delivery times. You ship your products to one facility, and the provider scatters them across the country without asking. Each state where your inventory lands becomes a state where you owe sales tax.
Amazon operates fulfillment centers in more than a dozen states. Larger FBA sellers often register proactively in every state with an Amazon warehouse because inventory can show up at any time. Smaller sellers sometimes wait until they see sales activity from a particular facility, but that approach carries risk: nexus existed the moment the inventory arrived, not the moment a sale happened. Any tax you should have collected between those two dates is still owed.
The fact that you didn’t choose to put inventory in a given state doesn’t help you. Tax authorities hold the inventory owner responsible regardless of how the goods got there. Your fulfillment partner has no obligation to manage your tax compliance, and their contracts almost universally say so. Monitoring where your inventory sits is your problem, and falling behind on it is the most common way e-commerce sellers end up with multi-state back-tax exposure.
State Income Tax: The Second Obligation
Most sellers focus on sales tax and never look at income tax. A federal law known as Public Law 86-272 protects certain businesses from state income tax when their only in-state activity is soliciting orders for tangible goods that are approved and shipped from outside the state.1Office of the Law Revision Counsel. United States Code Title 15 Section 381 – Imposition of Net Income Tax Many online sellers assume it covers them. It doesn’t, the moment you store inventory in a state.
Maintaining a warehouse in a state is explicitly classified as an unprotected activity under the Multistate Tax Commission’s interpretation of P.L. 86-272. The same applies to consigning stock to any third party for sale, or keeping goods in a state beyond what’s needed for sales samples. Once you cross that line at any point during a tax year, all of your income attributable to that state loses protection for the entire year.2Multistate Tax Commission. Statement of Information Concerning Practices of Multistate Tax Commission and Signatory States Under Public Law 86-272
An FBA seller with inventory in eight states likely has state income or franchise tax filing obligations in all eight, on top of sales tax duties. Sellers who diligently collect sales tax but never file state income tax returns are building a separate liability they often don’t know about.
Marketplace Facilitator Laws Don’t Fully Solve This
All states with a sales tax have enacted marketplace facilitator laws, which require platforms like Amazon, Etsy, and Walmart Marketplace to collect and remit sales tax on behalf of their third-party sellers. If you sell exclusively through such a marketplace, you might not need to register for a sales tax permit in certain states for those specific sales.
That’s not a clean escape. If you make any sales outside the marketplace, through your own website, at a trade show, or via phone orders, you still need to register and collect tax yourself in states where you have nexus. Some states also require registration regardless of whether the marketplace handles collection. The registration obligation and the collection obligation are separate questions.
Marketplace facilitator laws also only cover sales tax. They do nothing about the state income tax obligations that warehouse storage creates.
Economic Nexus Can Add More States
Even in states where you have no inventory, you can still owe sales tax based on sales volume alone. The 2018 Supreme Court decision in South Dakota v. Wayfair, Inc. overruled the earlier rule requiring physical presence, holding that economic activity by itself can create a sufficient connection.3Supreme Court of the United States. South Dakota v. Wayfair, Inc.
Nearly every state with a sales tax has since adopted an economic nexus threshold. The most common standard is $100,000 in annual sales into the state, though some states set higher bars, and roughly 19 jurisdictions also use a 200-transaction alternative test. California and Texas set their threshold at $500,000. So the total count of states where you need to register may combine physical nexus from warehouses and economic nexus from sales.
Mapping Where Your Inventory Has Been
Before you can register anywhere, you need to know where your inventory has been and when it arrived. Pull detailed inventory reports from every fulfillment partner or logistics provider. You need the physical address of each warehouse, the date your goods first entered that location, and the value of goods stored there over time. Amazon Seller Central provides inventory event detail reports that show transfers between fulfillment centers, though the data isn’t always easy to parse.
Once you have the location data, check it against each state’s sales tax and income tax nexus rules. Most state revenue departments publish nexus questionnaires that walk through the in-state activities that create nexus, including property ownership, use of representatives, and warehouse storage.
Registering and Collecting
Each state where you have nexus requires its own sales tax permit or seller’s license. You apply through the state’s department of revenue, providing your Federal Employer Identification Number, business entity details, and the date you first had taxable activity in the state. Most states issue permits for free. A few charge one-time fees up to $100, and some require a refundable security deposit.
If you need to register in many states at once, the Streamlined Sales Tax Registration System lets you apply in 24 participating states through a single free online form.4Streamlined Sales Tax Governing Board. Sales Tax Registration SSTRS For states outside the system, you register through each state’s portal individually.
After registration, the state assigns a filing frequency based on your expected sales volume. You must file a return for every period even if you had zero taxable sales; skipping a period generates a failure-to-file penalty in most states. Sales tax rates vary by state, county, city, and special taxing district, so most multi-state sellers rely on tax automation software that calculates the correct rate at checkout.
Cleaning Up Past Exposure
Sellers who discover they should have been collecting for years face an uncomfortable choice. Registering normally means the state may ask when nexus actually began and pursue back taxes, penalties, and interest for the full exposure period. A voluntary disclosure agreement offers a better path: you come forward, agree to file returns for a limited lookback period, and the state waives penalties in exchange.
The Multistate Tax Commission runs a national voluntary disclosure program that covers most participating states through a single application. Lookback periods for sales tax range from three to five years depending on the state. For sellers with only economic nexus and no physical presence, many states start the lookback no earlier than their economic nexus effective date. The MTC requires a minimum of $500 in estimated tax due per state to process an application.5Multistate Tax Commission. Multistate Voluntary Disclosure Program
One critical exception: sales tax you actually collected from customers but never remitted typically must be paid in full regardless of the lookback period, and may carry penalties that can’t be waived.6Multistate Tax Commission. Voluntary Disclosure Program Lookback Period Chart Holding onto tax money customers paid is treated far more seriously than failing to collect it. The distinction between “didn’t collect” and “collected but didn’t remit” can be the difference between a manageable settlement and a fraud investigation.
What Non-Compliance Costs
Ignoring nexus obligations makes them more expensive over time. States charge both penalties and interest on unpaid sales tax, and those amounts compound. Late filing penalties are commonly assessed as a percentage of unpaid tax for each month the return is overdue, and interest accrues daily. A seller who had nexus in a state for four years without registering can face a bill that dwarfs the underlying tax.
States can also pursue personal liability against business owners and officers. When a business collects sales tax from customers but fails to remit it, the individuals who controlled the company’s finances can be held personally responsible for the unpaid amount. That liability can survive even if the business dissolves or goes bankrupt. A responsible person is generally anyone with authority over tax payments, which can include a CFO, controller, or managing member, not only the owner.
States share information with each other more aggressively than they used to, and registering in one state can prompt inquiries from neighbors that notice your inventory data. If a state discovers you through an audit rather than a voluntary disclosure, you lose access to the penalty waivers and limited lookback periods that VDAs provide. Coming forward before a state finds you is almost always cheaper than waiting.