US LLCs for Non-Residents: Mastering Sales Tax Nexus in 2026

Sales tax nexus describes the necessary connection between your US LLC and a state that compels you to collect and remit sales tax. Without nexus in a state, you are generally not required to collect sales tax from customers in that state. With nexus, however, it becomes a legal obligation.

For non-US founders, the challenge often lies in recognizing that nexus can be established without a physical presence. The Wayfair v. South Dakota Supreme Court decision in 2018 fundamentally changed sales tax laws, allowing states to impose collection duties based on sales volume or transaction count, known as economic nexus.

Even as a non-US resident, certain activities within a US state can establish physical nexus for your LLC. This includes having a physical office, warehouse, or retail store. Even temporary presence, like attending trade shows where you make sales, can create short-term nexus.

Using third-party services like fulfillment by Amazon (FBA) also creates physical nexus. If your inventory is stored in an Amazon warehouse in Texas, you likely have physical nexus in Texas. It is crucial to track where your inventory is located, as this dictates where you must register for sales tax permits.

Economic nexus is the most common trigger for remote sellers in 2026. Most states have adopted thresholds, typically $100,000 in gross sales or 200 separate transactions into the state within a calendar year. Once your LLC crosses either threshold, you establish economic nexus.

These thresholds vary slightly from state to state. For example, some states only count gross sales, while others count both. Staying current with each state's specific rules is complex, requiring careful monitoring of your sales data for all 50 states.

Beyond physical and economic factors, other types of nexus can trigger sales tax obligations. Affiliate nexus arises if your LLC has agreements with in-state individuals or businesses who refer sales to you in exchange for a commission. Their physical presence can be attributed to your business.

Click-through nexus is similar. If you pay a commission to an in-state resident for sales generated through a link on their website, some states may consider that a form of nexus. These rules are less common but still apply in certain jurisdictions, adding another layer of complexity for non-US founders.

If your US LLC establishes nexus in a state, you must register for a sales tax permit before collecting sales tax. Collecting sales tax without a valid permit is illegal and can result in severe penalties. Most states have online registration portals.

After registration, you must collect the correct sales tax rate from your customers in that state and file periodic returns, usually monthly, quarterly, or annually. Penalties for late filing, underpayment, or non-filing can include fines, interest, and even criminal charges in extreme cases.

Managing multi-state sales tax manually is nearly impossible for most businesses. E-commerce platforms often have built-in sales tax calculation features, but these may not cover all state and local nuances. Integrating with specialized sales tax automation software is highly recommended.

Providers like TaxJar, Avalara, or Stripe Tax can calculate sales tax in real time, help with registration, and automate filing. While these services have a cost (e.g., $19 to $99 per month for small businesses), they significantly reduce compliance risk and save countless hours.