Ecommerce Tax Guide 2026: Sales Tax, Nexus, and What Sellers Need to Know

In 2026, online sellers must collect sales tax in every state where they have economic nexus, typically around $100K in sales or 200 transactions. Marketplace facilitator laws mean Amazon and Walmart handle tax on their platforms, but you still owe tax on your own Shopify sales. FBA sellers pick up physical nexus in many states through inventory placement, and international sellers face VAT and GST abroad. This guide walks through the obligations, deadlines, and compliance strategy.

Ecommerce tax is not optional and it is not simple. Since the 2018 Wayfair decision gave states the power to tax remote sellers, the rules have grown more complex every year. Most states plus DC charge sales tax, each with its own rates, rules, and filing frequencies.

Ignore it and you face back taxes, penalties (often in the range of 10 to 25 percent of unpaid tax), and interest that compounds. This guide covers what you need to stay compliant without living inside tax paperwork. It is general information, not tax advice, so confirm the specifics for your situation with a qualified professional.

Sales tax fundamentals for online sellers

Sales tax is a consumption tax the seller collects at the point of sale and remits to the state. In most states the rate is based on the destination of the shipment, not your business location. Four concepts do most of the work:

• Physical nexus: an office, warehouse, employee, or inventory in a state. This affects FBA sellers and anyone with a warehouse.
• Economic nexus: exceeding a revenue or transaction threshold in a state. This affects all online sellers above the thresholds.
• Marketplace facilitator: the platform collects and remits tax for you. This applies to Amazon, Walmart, Etsy, and eBay sellers.
• Origin vs. destination: whether the rate is based on the seller or the buyer location. Most states use destination.

Economic nexus: state-by-state thresholds

Every state with sales tax now has an economic nexus law. Most use a $100K revenue threshold, but several differ:

• $100K revenue or 200 transactions: most states use this combined threshold.
• $100K revenue only, no transaction count: several large states, including California, Florida, and Texas.
• Higher revenue thresholds: a few states set the bar higher, and thresholds change, so verify the current figure per state.
• No statewide sales tax: Alaska (local only), Delaware, Montana, New Hampshire, and Oregon.

For FBA sellers this is the trap: Amazon spreads your inventory across fulfillment centers nationwide, and inventory in a state creates physical nexus there regardless of whether you have crossed the economic threshold. Check your FBA inventory placement reports quarterly.

Marketplace facilitator laws explained

Marketplace facilitator laws require platforms like Amazon, Walmart, Etsy, and eBay to collect and remit sales tax on your behalf. As of 2026, all states with sales tax have these laws in effect.

What they cover:

• Amazon collects and remits sales tax on all Amazon.com orders.
• Walmart Marketplace handles tax on Walmart.com orders.
• Etsy, eBay, and TikTok Shop handle tax on their platforms.

What they do not cover:

• Your own Shopify store. You must collect and remit tax yourself.
• B2B sales with tax-exemption certificates.
• Filing requirements. Many states still require a return even when the marketplace collected all the tax.
• Use tax on items you buy for business use.

Setting up sales tax on Shopify

Shopify offers built-in tax calculation, but you have to configure it correctly:

1. Determine your nexus states. List every state where you have physical presence or have exceeded economic thresholds.
2. Register for sales tax permits. Register in each nexus state before collecting. Collecting without a permit is illegal in most states.
3. Enable Shopify Tax. Under Settings, Taxes and duties, turn on automatic calculation for each registered state.
4. Verify product taxability. Some products are exempt or taxed at reduced rates, such as clothing or food in certain states. Set the correct tax category per product.
5. File and remit on schedule. Each state assigns a filing frequency (monthly, quarterly, or annually) based on your volume.

International VAT and GST

If you sell internationally, you face a different system entirely. VAT (Value Added Tax) and GST (Goods and Services Tax) apply in most countries outside the United States. Rough shape of the major regions:

• European Union: VAT, generally in the high teens to high twenties in percent depending on the country, with an IOSS scheme for low-value shipments.
• United Kingdom: VAT at 20 percent, with a registration threshold for UK sellers and a much lower bar for non-UK sellers.
• Canada: GST plus provincial tax, combining to roughly 5 to 15 percent depending on the province.
• Australia: GST at 10 percent above an annual registration threshold.
• Japan: consumption tax at 10 percent above an annual threshold.

EU IOSS (Import One-Stop Shop). For shipments to the EU valued under 150 euros, IOSS lets you charge VAT at checkout and remit it through a single EU filing. This speeds up customs clearance and avoids surprise duties at delivery.

• Register for IOSS through an intermediary if you are based outside the EU.
• Charge the destination country's VAT rate at checkout.
• File monthly returns through your IOSS portal.
• Include the IOSS number on shipping labels for customs.

Tax filing calendar for 2026

Missing a deadline triggers penalties and interest. The key recurring dates:

• Federal income tax (sole proprietor): annual, due mid-April of the following year.
• Federal estimated tax: quarterly, in April, June, September, and January.
• State sales tax: monthly or quarterly, often due around the 20th of the following month, varying by state.
• EU VAT (IOSS): monthly, due by the end of the month after the reporting period.
• UK VAT: quarterly, due about one month and seven days after the quarter ends.

Deductions every ecommerce seller should claim

These reduce your taxable income, and many sellers miss several of them:

• Cost of goods sold: product cost, freight, duties, packaging.
• Advertising: Meta, Google, TikTok, and influencer payments.
• Software and SaaS subscriptions: your storefront, email, analytics, and design tools.
• Shipping and fulfillment costs.
• Home office: a percentage of rent, utilities, and internet for dedicated space.
• Professional services: accountant, lawyer, and bookkeeper fees.
• Product photography and content creation.
• Business insurance.
• Inventory losses: damaged, expired, or obsolete stock.
• Vehicle expenses: drives to warehouses, suppliers, or the post office, with a mileage log.

Sales tax automation tools

Manual sales tax compliance across twenty-plus states is impractical. A few tools automate the process:

• TaxJar targets small-to-mid sellers and can auto-file in many states.
• Avalara handles complex multi-state sellers with coverage across a very large number of jurisdictions.
• Shopify Tax is built into Shopify, so there is no extra integration for Shopify-only sellers.
• Vertex serves enterprise sellers and adds international VAT support.

Whichever you choose, the point is the same: automated tools track your sales volume per state and calculate the right rate per jurisdiction, so you find out you are approaching a nexus threshold before you cross it rather than after.

Key takeaways

• You owe sales tax in every state where you have physical or economic nexus, and most thresholds sit around $100K in sales.
• Marketplace facilitator laws mean Amazon handles tax on Amazon sales, but your Shopify direct sales are your responsibility.
• FBA inventory creates physical nexus in every state where Amazon stores your products.
• International sales require VAT or GST registration, and the EU IOSS simplifies this for low-value orders.
• Register for permits before collecting. Collecting without registration is illegal.
• Use automated tools for multi-state filing. Manual filing across many states is impractical and error-prone.

Frequently asked questions

Do I need to collect sales tax if I sell less than $100K per year? You still owe tax in states where you have physical nexus, such as your home state or FBA warehouse states. The $100K figure applies to economic nexus only, and some states add a transaction threshold you might hit first. Always register in your home state regardless of revenue.

What if I have not been collecting tax but should have? Most states offer voluntary disclosure agreements that reduce penalties for coming into compliance on your own, typically with a limited lookback and reduced or waived penalties. Consult a sales tax professional before filing one, because the terms vary significantly by state.

Is shipping taxable? It depends on the state. Some tax shipping charges, some exempt them if listed separately, and some have rules based on how shipping is billed. Automation tools handle this per jurisdiction. As a general rule, if shipping is built into a free-shipping product price, the full amount is taxable.

Do I charge VAT on digital products sold internationally? Generally yes. The EU, UK, and many other countries require VAT on digital products and services sold to consumers, and the EU's OSS system lets you file a single return across EU countries. If you sell subscriptions or downloads internationally, you likely have VAT obligations.