The U.S. Sales Tax Guide for Canada-Based Businesses

Do Canadian Companies Charge U.S. Sales Tax?

Yes. A Canadian company must charge U.S. sales tax once it has nexus in a state, meaning either physical presence or economic activity above that state’s threshold. No U.S. entity, subsidiary, or physical location is required. The rules apply to foreign sellers exactly as they apply to domestic ones, following South Dakota v. Wayfair, Inc. (2018).

Two triggers create the obligation:

• Physical nexus: inventory, people, or property in a state.
• Economic nexus: sales or transactions into a state above its threshold.

It reaches every channel. You collect on your own e-commerce store, you may still owe on marketplace sales, and Software as a Service can be taxable depending on the state.

How Is U.S. Sales Tax Different From GST/HST?

U.S. sales tax is a single-stage retail tax collected only at the final sale to the consumer. GST/HST is a multi-stage value-added tax (VAT) with input tax credits that let registered businesses recover the tax they pay on inputs. U.S. sales tax has no such credit. Businesses avoid tax on inputs through resale exemptions instead.

U.S. sales tax that your business pays is not recoverable through input tax credits. Plan for it as a cost unless you can claim a resale exemption.

What Is Sales Tax Nexus?

Nexus is the connection between a business and a state that triggers the duty to register, collect, and file sales tax. Two kinds exist. Physical nexus comes from a presence in the state. Economic nexus comes from sales volume. A Canadian seller can trigger either one without any U.S. address.

What Creates Physical Nexus for a Canadian Seller?

Inventory, people, or property in a state create physical nexus. For Canadian sellers, the top trap is Fulfillment by Amazon (FBA) inventory stored in a U.S. warehouse, which creates nexus the moment Amazon places your stock there.

Common physical nexus triggers:

• FBA inventory stored in a state (the most common surprise for Canadian sellers).
• Inventory held by a third-party logistics (3PL) provider.
• Warehouses or storage locations.
• Employees, contractors, or sales representatives.
• Offices or other physical premises.
• Trade show attendance (rules vary by state).

How Did the Wayfair Decision Change Things for Canadian Sellers?

South Dakota v. Wayfair, Inc. let states tax remote sellers that have no physical presence. The Supreme Court decided it on June 21, 2018, at 585 U.S. 162, overturning Quill Corp. v. North Dakota (1992). The decision applies to foreign sellers. A Canadian company with enough U.S. sales now triggers economic nexus.

The South Dakota law upheld in Wayfair set the model threshold at $100,000 in sales or 200 transactions per year. Many states have since dropped the 200-transaction prong, including California, Colorado, Iowa, Maine, Massachusetts, North Dakota, Washington, and Wisconsin. South Dakota itself dropped it effective July 1, 2023, leaving a single $100,000 gross-sales threshold.

What Are the Economic Nexus Thresholds by State?

Most states use $100,000 in sales or 200 transactions per year, but the biggest markets set their own rules. California and Texas use a $500,000 sales-only test. New York requires both $500,000 and 100 transactions. The table below shows the thresholds that catch most Canadian sellers.

Measurement differs by state. Some count gross sales, some count retail sales, and some count only taxable sales. The lookback period also varies, from the current or previous calendar year to a rolling 12 months. Check each state’s rule before you assume you are under the line.

Which U.S. States Have No Sales Tax?

Five states levy no statewide sales tax. They are New Hampshire, Oregon, Montana, Alaska, and Delaware, known as the NOMAD states. Alaska is the exception that matters. Its local governments levy sales tax through the Alaska Remote Seller Sales Tax Commission (ARSSTC), so Alaska is not obligation-free for remote sellers.

Some no-tax states still expect you to report exempt sales, so confirm reporting duties even where no tax applies.

Does Amazon Collect Sales Tax for Canadian Sellers? Marketplace Facilitator Laws Explained

Yes. Every U.S. sales tax state now has marketplace facilitator laws that require Amazon, eBay, Etsy, and Walmart to collect and remit sales tax on marketplace sales. That does not end your own obligations. Three gaps remain for Canadian sellers.

1. Marketplace sales still count toward your threshold in some states. Your Amazon volume can push you over economic nexus, forcing registration for your direct Shopify sales.
2. Some states still require registered sellers to file returns. You may owe zero or informational returns even when the marketplace remits everything.
3. FBA inventory creates physical nexus on its own. An FBA-only seller can still owe registration and filings, independent of facilitator collection.

How Does a Canadian Business Get an EIN?

Most states require a U.S. Employer Identification Number (EIN) before they issue a sales tax permit, and foreign entities cannot use the IRS online EIN tool. You apply by filing Form SS-4 by fax or phone through the IRS international applicants line.

The common stumbling block is the responsible party line on Form SS-4. Foreign founders often have no U.S. Social Security Number (SSN) or Individual Taxpayer Identification Number (ITIN). A few states accept registration without an EIN, but most require one first.

How Do You Register for a U.S. Sales Tax Permit From Canada?

Register with each nexus state’s Department of Revenue (DOR), mostly online, after gathering your Canadian business number, EIN, business structure, and estimated sales volume. The Streamlined Sales Tax Registration System (SSTRS) lets one application cover 24 member states, a major shortcut for foreign sellers.

Watch for the realities that trip up out-of-state sellers:

• Some states require a bond or security deposit from foreign sellers.
• Some states require a registered agent in-state.
• Collecting tax without a permit is illegal in most states.
• A sales tax permit is not a business license. They are separate.
• Some states require your permit number on invoices.

How Do You Collect U.S. Sales Tax at Checkout?

Charge the combined state, county, city, and district rate based on the buyer’s location, because most states use destination sourcing. Platforms like Shopify and BigCommerce automate the calculation once you configure each nexus state. Product taxability rules still differ by state.

Use the Commenda sales tax calculator to look up a rate for a buyer’s address. The calculator returns rates only. To check whether you have crossed a state’s threshold, use the economic nexus exposure guide.

How Do Exemption and Resale Certificates Work?

When a U.S. buyer purchases for resale or holds exempt status, you do not charge tax, but only if you collect a valid exemption or resale certificate at the time of sale. You validate the buyer’s permit number and retain the certificate for audit defense. Missing certificates make you liable for the uncollected tax.

The process is simple. The buyer gives you the state’s certificate form, or a multistate certificate where accepted. You confirm the permit number and file the certificate. This is the U.S. counterpart to input tax credits. Business buyers avoid tax through an exemption at the point of sale, not through recovery on a return.

How Do You Remit U.S. Sales Tax From Canada?

File and pay each nexus state separately through its DOR portal, on the frequency the state assigns at registration. Monthly, quarterly, and annual schedules all exist. Higher volume means more frequent filing. Many states require a zero return even in periods with no sales.

What filing frequency will you get?

States set your frequency by sales or tax liability volume. High-volume sellers file monthly. Low-liability sellers may file annually. Each state publishes its own dollar bands and assigns your schedule when it issues the permit. California’s Department of Tax and Fee Administration (CDTFA), for example, sets your frequency from your reported or anticipated taxable sales. Read the frequency printed on your permit rather than guessing.

How do you actually pay from a Canadian bank?

Most state portals default to Automated Clearing House (ACH) debit, which requires a U.S. bank account. Canadian bank accounts are routinely rejected for ACH setup. Your alternatives are an international wire, which carries higher per-payment fees, or a credit card where the state accepts it, usually for smaller amounts. Many Canadian sellers open a U.S. dollar or U.S.-domiciled account to avoid recurring wire costs.

Which currency do you report in?

U.S. returns are filed and paid in U.S. dollars (USD). You report the USD amounts you actually charged. Convert to Canadian dollars only in your Canadian books and GST/HST reporting, never on the state return. The common error is converting USD sales to CAD and reporting the converted figure.

Is SaaS Taxable in the U.S. for Canadian Companies?

Roughly half of U.S. states tax Software as a Service (SaaS), and taxability depends on each state’s classification. Texas taxes SaaS as a data processing service, per the Texas Comptroller. California generally exempts it, per the CDTFA. Your obligation turns on the customer’s billing location (the physical address, not the IP), the state’s taxability rule, and whether you cross nexus.

What Happens If a Canadian Business Ignores U.S. Sales Tax?

You face penalties, interest, and back-tax assessments. States can audit three to six years back, and the lookback can run longer or be unlimited if you never registered. The liability compounds, because uncollected tax becomes the seller’s own debt.

Protect yourself with records. Keep digital records for six or more years, and reassess your nexus every year as sales grow. A voluntary disclosure agreement (VDA) can cap the lookback and waive penalties for sellers who come forward before a state makes contact.

How We Help Canadian Businesses With U.S. Sales Tax

Commenda’s global indirect tax software tracks your physical and economic nexus across all U.S. states, handles registrations, calculates the right rate at checkout, and files your returns on schedule. It is built for cross-border sellers running Shopify, Amazon, and 100+ ERP and API integrations.

Monitor your exposure with the economic nexus exposure guide and look up rates with the sales tax calculator. Book a demo to get a free assessment of your U.S. nexus exposure from Canada.