OTTAWA – A Canadian steel company shipping coils to Michigan may owe no ordinary U.S. duty if its goods qualify under USMCA, while an American business importing Canadian auto parts could face a different rate based on classification, origin, and current trade measures. The tariff isn’t simply chosen by the president or charged at a border officer’s discretion.
Instead, tariffs come from trade laws, USMCA/CUSMA rules, agency investigations, executive actions, and Customs and Border Protection regulations. This guide explains who has authority, how origin rules affect the final rate, how customs calculates the amount owed, and what importers should check before shipping, including the legal basis for U.S. tariffs. Rates and temporary measures can change, so verify current CBP, Federal Register, USTR, and Canadian government notices before relying on any example.
Key Takeaways
- Tariffs depend on the product’s HTSUS classification, customs value, country of origin, and any temporary trade action.
- USMCA can reduce ordinary duties to zero when goods meet product-specific origin rules and the importer supports the claim. See CBP’s USMCA guidance.
- Executive orders, presidential proclamations, and congressional laws can add duties beyond regular tariff rates, sometimes with separate exemptions.
- Rates can differ for energy, steel, agricultural goods, transshipped products, and other sectors, so check the Harmonized Tariff Schedule before shipping.
- Importers should verify current CBP, USTR, White House, and Canadian customs notices before calculating costs.
How Tariffs Actually Get Set in the United States and Canada
Tariff decisions follow a legal chain. Legislatures create the authority, governments set trade policy under that authority, and customs agencies calculate and collect the amount at import.
The final charge depends on the product’s tariff classification, country of origin, customs value, trade program, and any special measure. Most tariffs are percentages of value, although some use a fixed amount per unit.
What Congress, the President, and trade agencies each control
Congress supplies the main U.S. legal framework through laws such as the Tariff Act of 1930 and the Trade Act of 1974. It can also limit, approve, or change executive tariff powers. The Congressional Research Service guide to import authority explains how these powers are divided.
The President can act only through authority that Congress has provided. For example, Section 232 is a national security process led by the Department of Commerce. Commerce investigates whether imports threaten national security, then the President decides whether to impose tariffs, quotas, or another remedy.
Section 301 follows a different path. The Office of the U.S. Trade Representative investigates unfair or discriminatory foreign trade practices and can recommend tariffs or other actions.
Section 122 of the Trade Act of 1974 gives the President temporary surcharge authority for serious balance-of-payments problems. The surcharge can reach 15% and generally lasts no more than 150 days unless Congress extends it. See the latest Section 122 tariff discussion.
IEEPA is a separate emergency-powers lane. As of August 2026, the Supreme Court has ruled that IEEPA does not authorize tariffs, and CBP has stopped collecting those duties. Refunds and related litigation remain active, so check the current legal position before publication or shipment.
Canada follows its own process. Parliament creates customs legislation, while the Department of Finance develops federal tariff policy and the government may announce trade measures under Canadian law and CUSMA rules.
Why CBP and CBSA collect tariffs but do not freely choose the rate
CBP in the United States and CBSA in Canada administer the border. They classify goods, review origin and customs value, collect duties, and can reassess an entry after release.
A customs officer cannot negotiate a lower tariff rate at the counter. Importers remain responsible for accurate descriptions, tariff classifications, commercial invoices, origin records, and payment. If those details change, the final duty can change too.
The U.S. Tariff Authorities That Can Change What Canada Pays
Several U.S. legal routes can change the duty on Canadian imports. The trigger, lead agency, and outcome differ, so one tariff doesn’t always replace another.
Section 232 tariffs respond to national security findings
The Department of Commerce investigates whether imports threaten U.S. national security. After Commerce issues a finding, the President may adjust imports through tariffs, quotas, or other measures. Steel and aluminum are the clearest examples.
Current proclamations may place covered products under a 25% or 50% duty, depending on the product, effective date, and applicable tariff instructions. Those rates are not permanent guarantees. Importers must check the latest CBP Section 232 guidance, presidential proclamations, Federal Register notices, and HTSUS Chapter 99 provisions.
Derivative goods create another cost risk. In some cases, CBP assesses the duty on the full customs value of the imported product, rather than only the value of the steel or aluminum inside it. A Canadian product containing a small amount of covered metal can therefore face a larger duty than its metal content alone would suggest.
Section 301 targets unfair trade practices and can add another duty
Section 301 addresses a different problem. The Office of the U.S. Trade Representative investigates foreign acts, policies, or practices that are unjustifiable, unreasonable, discriminatory, or harmful to U.S. trade rights.
The process usually includes a public notice, investigation, findings, proposed action, and an opportunity for comments or hearings. USTR then decides whether to impose tariffs or another remedy. Unlike Section 232, which relies on national security authority, Section 301 focuses on trade practices.
That distinction matters for Canadian importers because both legal tests can apply to one product. Section 301 and Section 232 duties may stack, creating a combined rate.
Temporary and emergency tariff powers have different limits
Section 122 can support a broad, temporary surcharge for serious balance-of-payments problems. The statute caps that surcharge at 15% and generally limits it to 150 days, unless Congress extends it.
Emergency authorities such as IEEPA follow a separate legal path, and their use can change after presidential orders or court rulings. Before relying on any temporary tariff, check the latest order, court decision, and CBP implementation notice. Current U.S. tariff authority plans can also shift as one authority becomes unavailable and agencies use another.
Fast Facts and Costs Table: What Determines the Final Duty
The final duty depends on more than the headline tariff rate. Customs looks at the product, its origin, eligibility for preferential treatment, and the value used for duty calculation.
| Factor | Plain-language meaning | Effect on cost |
|---|---|---|
| Tariff classification | The HTSUS or Canadian tariff code assigned to the product | Sets the ordinary duty rate and may trigger special measures |
| Country of origin | Where the goods were produced under customs rules | Determines applicable tariffs, including Canada-specific measures |
| USMCA/CUSMA eligibility | Whether the shipment meets the agreement’s origin requirements | May reduce ordinary duty to zero, but not always other fees |
| Customs value | The value customs uses to assess percentage-based duties | A higher declared value creates a higher duty |
| Ordinary tariff rate | The standard percentage or per-unit charge | Applies before additional trade remedies |
| Special duties | Measures such as Section 232, antidumping, or countervailing duties | Can add substantial charges or stack with ordinary duty |
| De minimis treatment | Low-value treatment available only to qualifying shipments | May reduce or remove duty collection, subject to current rules |
| Additional fees | Brokerage, processing, harbor, tax, storage, and compliance costs | Raises the shipment’s total landed cost |
Customs value is the starting point for most percentage-based duties
For many U.S. imports, transaction value is the common starting point. That usually means the price paid or payable for the goods, adjusted where customs rules require. The declared amount must match and be supported by commercial records, such as the invoice, purchase order, and payment documents. CBP explains that the commercial invoice should show the price paid for the goods in its commercial invoice valuation guidance.
If the customs value is $10,000 and the duty rate is 25%, the duty is $2,500. Special products, related-party transactions, royalties, and goods without a reliable sale may require different valuation rules.
That $2,500 is only one part of landed cost. Freight, insurance, brokerage, merchandise processing fees, harbor maintenance fees, excise taxes, storage, compliance work, and trade remedy duties can raise the final bill. Current U.S. trade costs and tariff pressures can also affect shipping decisions.
A low-value shipment is not automatically duty-free
De minimis treatment can reduce or remove duty collection in qualifying cases, but thresholds and exclusions change. As of August 2026, the former U.S. $800 exemption isn’t a broad duty-free guarantee. Canada also uses different thresholds based on origin and shipping channel.
Low-value treatment doesn’t erase origin, admissibility, product safety, labeling, or documentation requirements. Before shipping, confirm the current CBP or CBSA threshold, transport rules, and product exclusions. The table is a planning framework, not a quote for a specific shipment.
Step-by-Step Guide to Checking a U.S.-Canada Tariff
A reliable tariff check starts with the product, not the seller’s country or a headline rate. Follow these steps before shipment, then compare your estimate with the filed entry.
Start with the product description and tariff classification
1. Record the product’s facts. Note its material, function, condition, dimensions, components, processing, and intended use. Include technical sheets, photos, assembly details, and the bill of materials.
2. Find the correct HTSUS code. The Harmonized System classification, not a casual name such as “machine part” or “metal fitting,” controls the tariff schedule. Search the current Harmonized Tariff Schedule and check the complete tariff line, including any Chapter 99 provisions.
When classification is uncertain, request a binding ruling or obtain professional customs advice before importing. Mixed-material goods, machinery, electronics, vehicles, and derivative steel or aluminum products deserve extra care. Classification can affect ordinary duty, USMCA eligibility, and special tariff programs.
Confirm origin, then test USMCA or CUSMA eligibility
3. Determine where the product originates. Shipping from Canada doesn’t automatically make a product Canadian-originating. A Canadian distributor may sell goods manufactured elsewhere, while a Canadian factory may use imported components.
4. Apply the product-specific origin rule. Check whether the required tariff shift, regional value content, or other rule applies. Then obtain the required certification or maintain records that support the claim. CBP’s USMCA FAQs explain the agreement’s origin requirements.
Goods that fail the rule usually fall back to the normal tariff schedule, even when the seller is located in Canada. They may also face separate trade measures discussed in current Canada-U.S. tariff coverage.
Check special measures, calculate the amount, and keep proof
5. Check current measures. Review the HTSUS, presidential proclamations, USTR notices, Commerce findings, CBP instructions, Canadian tariff notices, and any antidumping or countervailing duty order.
6. Calculate and verify. Multiply the customs value by each applicable percentage rate, then compare your estimate with the broker’s entry summary. Keep invoices, bills of materials, origin certifications, classification notes, and payment records.
7. Review after filing. Check the entry paperwork promptly. If you find an error, ask your broker about a post-summary correction or another permitted post-entry correction before deadlines expire.
USMCA and CUSMA: Why North American Origin Can Lower the Rate
The U.S.-Mexico-Canada Agreement, called CUSMA in Canada, can provide preferential tariff treatment for qualifying goods. However, a shipment from Canada does not automatically receive that preference because the seller or shipping address is Canadian.
Made in Canada is not the same as qualifying under the trade agreement
Suppose a Canadian company imports electronic parts from Asia, attaches them to a basic housing, and repackages the finished item in Canada. That activity may not change the product’s origin under the applicable USMCA rule. By contrast, substantial production in Canada may qualify if the product meets its required tariff shift, regional value content, labor value content, or another product-specific test.
The rule depends on the product’s tariff classification. Therefore, businesses should trace each major input and review how the Canadian operation changes the goods. Keep supplier declarations, invoices, bills of materials, and production records rather than relying on a “Made in Canada” label or a Canadian shipping address. Current CUSMA treatment under tariff measures can also depend on the legal authority behind the charge.
The certification can be flexible, but the records must be reliable
USMCA does not require one government-issued certificate form. An importer, exporter, or producer can complete the certification, provided it contains the required information about the parties, goods, tariff classification, origin criterion, and certification period. The CBP certification template shows the data a valid claim generally needs.
Still, flexibility in format does not reduce the proof requirement. Preserve the certification, supplier declarations, bills of materials, cost data, production records, invoices, shipping documents, and payment records. U.S. importers generally must retain supporting records for at least five years. Customs authorities can verify a claim after entry, then demand unpaid duties, interest, or penalties if the evidence falls short.
A trade preference may not remove every extra charge
USMCA preference usually addresses the ordinary customs duty. A qualifying product may still face Section 232, Section 301, safeguard, antidumping, countervailing, excise, or customs fees when the separate law applies.
Check every layer before quoting a landed cost. A valid origin claim can reduce one tariff while leaving another charge in place.
Local Tips and Common Mistakes to Avoid at the Border
Small documentation errors can create surprise tariffs, delayed releases, audits, or lost USMCA preference claims. Before shipping, compare the product description, origin evidence, classification, invoice, and expected landed cost.
Do not confuse the shipping country with the country of origin
A product routed through Canada or the United States may still originate in China, Mexico, or another country. A Canadian warehouse address proves where the seller stored the goods, not where the main manufacturing or transformation occurred.
Trace the production history and identify where the goods underwent their most important manufacturing step. Then check the applicable USMCA or CUSMA rule for that product and tariff classification. A Canadian warehouse, repackaging operation, or simple final-assembly step may not create Canadian origin.
Keep bills of materials, supplier statements, production records, and invoices that support the origin claim. The USMCA rules of origin also require importers to retain records supporting preferential treatment. When the production chain is complex, ask a licensed customs broker or trade specialist to review it, but remember that the importer remains responsible for the entry’s accuracy.
Watch for stacked duties, changing notices, and incomplete invoices
Check beyond the ordinary tariff rate. A shipment may also face a quota, surtax, Section 232 measure, antidumping or countervailing duty, or another trade remedy. Temporary notices can change quickly, so review the current HTSUS, CBP or CBSA instructions, and agency notices shortly before shipment.
Vague descriptions such as “parts” or “metal goods” create classification problems. Use the product’s material, function, model, quantity, and intended use instead. Match the commercial invoice, packing list, classification, origin claim, and customs entry. Even a low-value shipment can require accurate information when quotas or restricted goods apply.
Budget for the whole landed cost, not just the tariff
A low tariff rate can still produce an expensive shipment when customs value is high or extra paperwork applies. Write a landed-cost estimate before signing the sale or purchase contract. Include:
- Freight, insurance, brokerage, and customs fees.
- Storage, inspection, handling, and potential delay charges.
- GST, HST, sales taxes, or other import taxes.
- Currency changes, especially when invoices and duties use different currencies.
A broker can estimate entry charges, but request the assumptions in writing. Currency movements alone can alter the final bill, as tariff tensions affect the Canadian dollar. Use the estimate to set a realistic price and delivery schedule.
Frequently Asked Questions
Tariff questions often arise after the basic rate has been identified. These answers cover timing, refunds, rulings, and responsibility at the border.
Can a tariff change after the goods leave Canada?
Yes. The rate usually depends on the rules and tariff measures in effect when the goods enter the importing country. A shipment can also face a changed rate if customs finds a classification, origin, or valuation error during review. Check the current 2026 Canadian Customs Tariff and the U.S. HTSUS before filing the entry.
Who pays the tariff when a Canadian company sells to a U.S. buyer?
The importer of record generally pays U.S. duties and remains responsible for the entry’s accuracy. A sales contract can shift the economic cost to the seller through pricing or delivery terms, but it doesn’t remove the importer’s customs obligations. Confirm the Incoterms and duty responsibilities before signing the purchase agreement.
What happens if the importer paid too much?
The importer may seek a correction, refund, protest, or post-importation preference claim, depending on the error and filing deadline. For example, CBP allows certain USMCA refund claims when a later classification or valuation change directly affects origin eligibility. Keep the entry number, invoices, origin records, and supporting calculations.
Can a business get a tariff decision before shipping?
Yes. A U.S. importer can request a binding ruling from CBP on classification, origin, valuation, or trade-program eligibility. In Canada, CBSA advance rulings can address tariff classification, origin, and value for duty. A ruling gives the business a stronger basis for pricing and shipping decisions than an informal broker estimate.
Do tariffs apply equally to every product from Canada?
No. Rates can vary by tariff code, origin, product material, trade remedy, quota, and effective date. Steel, aluminum, vehicles, agricultural goods, and products with non-North American inputs may follow different rules. Current U.S.-Canada tariff developments can also affect which measures apply to a shipment.
