Understanding how tariffs work is essential for any business importing goods into the United States. The process involves classifying your product, determining which tariff rates apply, calculating the duty owed, and paying US Customs and Border Protection. In 2026, with multiple tariff programs stacking on top of each other, the system is more complex than ever. This guide walks you through each step with real examples.
Step 1: How Goods Are Classified (HTS Codes)
Every product imported into the US must be classified using the Harmonized Tariff Schedule (HTS). The HTS is a 10-digit coding system that assigns a unique number to every type of product. For example, HTS 8471.30.0100 covers laptop computers, while HTS 6110.20.2075 covers cotton sweaters. The first 6 digits are internationally standardized (used by most countries), while the last 4 digits are US-specific and determine the exact duty rate. Getting the HTS code right is critical — misclassifying your product can result in paying too much or too little duty, and CBP can impose penalties for incorrect classification. Most importers work with a licensed customs broker who specializes in HTS classification. You can also look up HTS codes using our HTS code search tool or the official USITC database.
Step 2: How Duty Rates Are Determined
Once your product has an HTS code, multiple duty rates may apply. The MFN (Most Favored Nation) base rate is printed in the HTS next to your code — this is the standard rate for WTO member countries, averaging about 3.4% but ranging from 0% to 30%+ depending on the product. On top of the MFN rate, additional tariffs may apply based on the country of origin and the product type. Section 122 adds 10% for most countries. Section 232 adds 25-50% for covered products (steel, aluminum, copper, autos, semiconductors, lumber) from all countries. Section 301 adds 25-100% for Chinese goods. Trade agreements like USMCA can reduce or eliminate rates for qualifying goods. The effective duty rate is the sum of all applicable rates.
Step 3: How Tariffs Are Collected
Tariffs are collected by US Customs and Border Protection (CBP) at the port of entry. Here's the process: Your goods arrive at a US port (seaport, airport, or land border crossing). Your customs broker files an 'entry' with CBP, declaring the goods, their HTS classification, country of origin, and customs value. CBP reviews the entry and may inspect the shipment. The duty amount is calculated based on the declared value and applicable rates. The importer pays the duty (usually electronically through the Automated Commercial Environment system). CBP releases the goods. Payment is typically due within 10 working days of entry. Most importers post a customs bond — a financial guarantee that ensures CBP will be paid. Single-entry bonds cover one shipment; continuous bonds cover all imports for a year.
Step 4: How Tariffs Stack (Section 122 + 232 + 301)
In 2026, multiple tariff programs can apply to the same shipment, and they stack — meaning you pay all of them. Here's how stacking works with a real example. Imagine importing $100,000 of steel pipe from China. MFN base rate: 0% (many steel products are duty-free at MFN). Section 122: 10% = $10,000. However, the anti-stacking rule applies — Section 232 products are exempt from Section 122 if Section 232 rate is higher. Section 232 steel: 50% = $50,000 (replaces Section 122 due to anti-stacking). Section 301: 25% = $25,000 (this DOES stack with Section 232). Total duty: $75,000 (75% effective rate). Now compare with steel from Germany: Section 232 steel 50% = $50,000 (no Section 301 since Germany isn't China). Total: $50,000 (50% effective rate). And steel from Canada with USMCA: Section 232 steel 50% = $50,000 (USMCA does NOT exempt Section 232 products). Total: $50,000 (50%).
Real Calculation Examples for 2026
Example 1 — Consumer Electronics from Vietnam: $200,000 of smartphones (HTS 8517.13). MFN rate: 0%. Section 122: 10% = $20,000. No Section 232 or 301. Total duty: $20,000 (10% effective rate). Example 2 — Clothing from Bangladesh: $50,000 of cotton t-shirts (HTS 6109.10). MFN rate: 16.5% = $8,250. Section 122: 10% = $5,000. No Section 232 or 301. Total duty: $13,250 (26.5% effective rate). Example 3 — Auto Parts from Mexico (USMCA qualifying): $500,000 of engine components. MFN rate: 2.5%. USMCA preference: 0% (eliminates MFN and Section 122). Total duty: $0. Example 4 — Semiconductors from Taiwan: $1,000,000 of chips (HTS 8542). MFN rate: 0%. Section 232 semiconductors: 25% = $250,000 (replaces Section 122 via anti-stacking). Total duty: $250,000 (25% effective rate).
The Difference Between Tariffs, Duties, and Taxes
While often used interchangeably, these terms have slightly different meanings. Tariffs are the rates set by law — the percentage or per-unit amount charged on imports. The Harmonized Tariff Schedule is the official listing of all US tariff rates. Duties are the actual amounts paid — when you apply the tariff rate to your shipment value, the result is the duty you owe. Taxes are broader government charges. Import duties are a type of tax, but they're distinct from income tax, sales tax, or VAT. Other import-related fees include the Merchandise Processing Fee (MPF, 0.3464% of value with a $31.67-$614.35 range), Harbor Maintenance Fee (HMF, 0.125% for ocean cargo), and customs broker fees (typically $150-250 per entry). These fees apply on top of tariffs and are not included in duty rate calculations.
How to Reduce Your Tariff Costs
There are several legal strategies to reduce tariff exposure. Free Trade Zones (FTZs): Import goods into an FTZ to defer or reduce duties — you can store, manufacture, or re-export without paying tariffs until goods enter US commerce. Trade agreements: USMCA can eliminate tariffs for qualifying Canada/Mexico goods. Tariff engineering: Modify products or their classification to qualify for lower rates — for example, importing components separately rather than assembled products may result in lower rates. Duty drawback: Claim refunds on duties paid for imported goods that are later re-exported. First Sale rule: Use the manufacturer's price rather than the middleman's price as the customs value, reducing the base on which tariffs are calculated. Country diversification: Source from countries with lower effective rates — Vietnam at 10% versus China at 35%+. Consult a licensed customs broker for strategies specific to your products.
Common Mistakes Importers Make
Incorrect HTS classification is the most common and costly mistake — it can result in overpaying duty or CBP penalties for underpayment. Failing to claim trade agreement preferences means paying tariffs you don't owe — an estimated 20% of USMCA-eligible shipments enter without claiming the preference. Not using a customs broker for complex shipments can lead to classification errors, missed deadlines, and compliance issues. Ignoring tariff stacking — many importers calculate only the Section 122 rate and are surprised by Section 232 or 301 charges. Undervaluing goods on customs declarations is illegal and can result in seizure, fines, and criminal penalties. Assuming de minimis still applies to China — the $800 exemption was eliminated for Chinese imports.
Key Takeaway
Tariffs work through a systematic process: classify your product with an HTS code, determine which tariff rates apply based on product type and country of origin, calculate the stacked duty amount, and pay CBP at the port of entry. In 2026, with Section 122, Section 232, and Section 301 all potentially stacking, getting this right is more important than ever. Use our tariff calculator for instant duty estimates, or explore our HTS code lookup tool to find the right classification for your products.
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