The landscape of US sales tax has undergone a seismic shift, and if you are selling into the American market, you simply cannot afford to look away. What used to be a fragmented system of individual seller responsibilities has evolved into a centralized, platform-driven model. These "Marketplace Facilitator Laws" are now the gold standard across the United States, and they have completely rewritten the rulebook for international brands and digital businesses.
Whether you are operating from the UK, Canada, or Australia, understanding how the IRS and individual states view your transactions is the difference between a thriving global expansion and a crushing tax audit. At Sterlinx Global, we see firsthand how daily IRS updates and state-level changes impact our clients' bottom lines. This is why staying compliant is no longer just a "back-office task", it is your new secret weapon for growth.
The Big Shift: From Seller Responsibility to Platform Accountability
Historically, the burden of collecting and remitting sales tax sat squarely on the shoulders of each individual seller. If you sold a widget to a customer in Florida, it was your job to figure out the tax rate, collect it, and send it to the state. However, as millions of small and international sellers flooded platforms like Amazon, Etsy, and Walmart, state governments realized they couldn't efficiently track everyone.
The solution? Marketplace Facilitator Laws.
These laws mandate that the "facilitator", the platform that lists products and processes payments, is now responsible for collecting and remitting sales tax on behalf of the third-party sellers using their platform. By 2026, every US state with a sales tax has some version of these rules in effect.
Understanding Economic Nexus in 2026
While the marketplace might collect the tax, your business still has to deal with "Economic Nexus." This is the legal threshold of economic activity that triggers your obligation to register with a state.
Common thresholds include:
- $100,000 in gross sales into a specific state.
- 200 or more separate transactions into a specific state (though some states are phasing this out).
Don't worry, just because you hit a threshold doesn't always mean you'll be paying more out of pocket. Often, it just means you need to register and report. However, the rules on how you calculate these thresholds vary wildly by state, making USA tax compliance matters more complex than they appear at first glance.
Who Exactly Is a Marketplace Facilitator?
The definition of a marketplace facilitator is broader than you might think. It isn't just restricted to retail giants like Amazon. In 2026, a platform is generally considered a facilitator if it:
- Lists or advertises products, services, or digital goods for sale.
- Processes payments or handles the checkout process for the buyer.
- Takes a fee or commission for the transaction.
This category now encompasses app stores, food delivery services, gig-economy platforms, and even B2B SaaS marketplaces. If you are selling through a third-party site that touches the money, they are likely your marketplace facilitator. This shift is a core component of the ultimate guide to global e-commerce expansion, as it simplifies collection but complicates registration requirements.
Why International Sellers Must Pay Attention
If you are an international seller, you might assume that because Amazon or eBay is collecting the tax, you are "off the hook." This is a dangerous misconception. The reality is that marketplace sales can still create "nexus" exposure for your business.
The Problem of "Mixed" Sales
If you sell through Amazon (marketplace) but also have your own Shopify store (direct-to-consumer), you are in a high-risk zone. Most states require you to count all sales, both marketplace and direct, to determine if you have reached the economic nexus threshold.
For example, if you sell $95,000 via Amazon and $6,000 via your own website into New Jersey, you have exceeded the $100,000 threshold. You must now register in New Jersey and collect tax on that $6,000 of direct sales. Failure to do so leads to penalties that far outweigh the tax itself.
The "Register but No Tax" Paradox
In some states, you are required to register for a sales tax permit even if the marketplace is collecting 100% of the tax for you. You then have to file "zero" returns or report the marketplace sales as "exempt." If you miss these filings, the state may assume you owe money based on your estimated volume and issue a default assessment.
State-by-State Complications You Can’t Ignore
The US doesn't have a single "Sales Tax." It has 45 different state-level systems and thousands of local jurisdictions. This is why a one-size-fits-all approach to US tax is impossible.
- Texas: Texas is notoriously strict. They prohibit facilitators from using simplified local rates in many cases. They require destination-based calculations, meaning the exact tax rate depends on the buyer's front door.
- Louisiana: Recent updates in 2023 and 2024 have changed how economic nexus is calculated, focusing on "retail sales" and requiring facilitators to include all platform sales when determining if they must register.
- Washington: Even if the marketplace collects sales tax, you might still owe the Business & Occupation (B&O) tax. This is a gross receipts tax that applies to your total revenue, regardless of who collected the sales tax at checkout.
Navigating these differences is essential to avoid mistakes with tax filings that can trigger audits across borders.
Actionable Checklist for 2026 Compliance
To stay ahead of the IRS and state tax authorities, follow this structured approach to your US operations.
- Map Your Sales Volume: List every US state where you have customers. Calculate your gross sales and transaction counts for the last 12 months.
- Differentiate Your Channels: Identify which sales went through a "Facilitator" (like Amazon) and which were "Direct" (your own site or manual invoicing).
- Check Threshold Rules: Determine if a state counts marketplace sales toward your nexus threshold. (e.g., Mississippi excludes them, but New Jersey includes them).
- Register Where Necessary: If you hit the threshold, register for a sales tax permit immediately. Do not wait for the state to contact you.
- Maintain Records: Keep certificates of proof or contracts from your marketplaces showing they are the "collector of record." This is your primary defense in an audit.
- Review Your Bookkeeping: Ensure your accounting software can distinguish between taxed and non-taxed transactions to prevent reporting errors.
How Sterlinx Global Simplifies US Tax Compliance
Managing US sales tax is a full-time job. Between shifting state laws and the need for daily monitoring, it is easy for international sellers to fall behind. This is where our global tax compliance suite comes in.
We don't just "advise" you on what to do; we handle the execution. You provide the data, and we complete the compliance. Our team monitors IRS and state-level changes daily to ensure your business remains in good standing across every jurisdiction you touch. From initial registration to ongoing monthly filings, we take the administrative weight off your shoulders.
By partnering with us, you gain a dedicated team that understands the intersection of VAT, GST, and US Sales Tax. We ensure that your expansion into the US market is built on a foundation of total compliance, allowing you to focus on scaling your brand.
Ready to secure your US tax position?
Contact us today to speak with an expert about your marketplace compliance.
Frequently Asked Questions
If Amazon collects my tax, why do I need a tax professional?
Amazon only collects tax on the sales made through their platform. They do not manage your economic nexus registrations, your filings for direct sales, or your corporate tax obligations. A tax professional ensures you aren't creating unregistered nexus that could lead to massive retroactive liability.
What is "Retroactive Liability"?
If you have had nexus in a state for years but never registered, the state can come after you for all the tax you should have collected plus heavy interest and penalties. In some cases, this can go back to 2018.
Do I need a US LLC to sell in the US?
Not necessarily. Many international sellers operate as foreign entities. However, whether you are a UK Limited Company or a Canadian Corporation, you still have "Sales Tax Nexus" if you sell to US residents.
Does the 2026 global e-commerce report cover these changes?
Yes, we keep our 2026 Global E-commerce reports updated with the latest US marketplace facilitator rules to help international sellers navigate cross-border trade.
What if I only sell digital goods?
Digital goods are taxable in many US states. Marketplace facilitator laws apply to digital marketplaces (like app stores or SaaS platforms) just as they do to physical goods. You must track your digital sales by state to ensure you haven't triggered economic nexus.