An HTS (Harmonized Tariff Schedule) code is a 10-digit classification number used by US Customs and Border Protection to identify imported goods and determine applicable duty rates. The first 6 digits are standardized internationally under the Harmonized System, while the last 4 digits are specific to the United States.

How are US tariff rates determined?

US tariff rates are set by Congress and administered by CBP. The base MFN (Most Favored Nation) rate applies to most trading partners. Additional special tariffs — such as Section 301 (China), Section 232 (steel and aluminum), and Section 122 (temporary global surcharge, 10–15% per Proclamation 11012) — may apply on top of the base rate. Note that Section 122 does not stack with Section 232: goods already subject to §232 actions are excluded from the §122 surcharge.

What are Section 301 tariffs?

Section 301 tariffs are additional duties imposed on Chinese goods under the Trade Act of 1974, in response to unfair trade practices. They range from 7.5% to 100% depending on the product category and apply on top of the standard MFN duty rate. Four separate lists cover approximately $370 billion of annual imports.

How do I find the tariff rate for my product?

Use the search bar on this site to describe your product in plain English — our AI identifies the correct HTS code and shows all applicable duty rates including base MFN, Section 301, Section 232, and any other overlays. You can also browse by HTS chapter or product category.

What is a landed cost?

Landed cost is the total cost of importing a product to its destination, including the product price (FOB), ocean or air freight, insurance, US Customs duties, Merchandise Processing Fee (MPF), Harbor Maintenance Fee (HMF), and any other applicable surcharges. It represents the true cost of an imported good before domestic distribution.

An HTS (Harmonized Tariff Schedule) code is a 10-digit classification number used by US Customs and Border Protection to identify imported goods and determine applicable duty rates. The first 6 digits are standardized internationally under the Harmonized System, while the last 4 digits are specific to the United States.

How are US tariff rates determined?

US tariff rates are set by Congress and administered by CBP. The base MFN (Most Favored Nation) rate applies to most trading partners. Additional special tariffs — such as Section 301 (China), Section 232 (steel and aluminum), and Section 122 (temporary global surcharge, 10–15% per Proclamation 11012) — may apply on top of the base rate. Note that Section 122 does not stack with Section 232: goods already subject to §232 actions are excluded from the §122 surcharge.

What are Section 301 tariffs?

Section 301 tariffs are additional duties imposed on Chinese goods under the Trade Act of 1974, in response to unfair trade practices. They range from 7.5% to 100% depending on the product category and apply on top of the standard MFN duty rate. Four separate lists cover approximately $370 billion of annual imports.

How do I find the tariff rate for my product?

Use the search bar on this site to describe your product in plain English — our AI identifies the correct HTS code and shows all applicable duty rates including base MFN, Section 301, Section 232, and any other overlays. You can also browse by HTS chapter or product category.

What is a landed cost?

Landed cost is the total cost of importing a product to its destination, including the product price (FOB), ocean or air freight, insurance, US Customs duties, Merchandise Processing Fee (MPF), Harbor Maintenance Fee (HMF), and any other applicable surcharges. It represents the true cost of an imported good before domestic distribution.

Best tariff API

Best Tariff API for US Duty Rates and HTS Data

Compare tariff APIs for HTS lookup, duty-rate stacks, landed-cost calculation, bulk classification, source freshness, and trade-remedy screening.

Updated June 2026Built for importer, broker, and compliance workflows

Open API docs API options

How we picked these tools

A tariff API should do more than return a code. Production teams need current HTS data, country-aware duty stacks, surcharge layers, bulk throughput, source freshness, and clear caveats around risk layers such as AD/CVD.

Supports HTS search, exact lookup, bulk lookup, and landed-cost calculation.

Returns structured duty layers rather than one opaque rate.

Includes source freshness, effective-date, and trade-remedy context where available.

Has self-serve keys, pricing, and documentation for developers.

Comparison

Pick 1

US Tariff Rates API

Developers building US tariff lookup, duty-rate, bulk classification, landed-cost, and compliance monitoring features.

Get API key

Strengths

REST endpoints for HTS search, lookup, bulk lookup, landed-cost calculation, trade-remedy screening, and source freshness.
Duty stack fields for base duty, Section 301, Section 232, Section 122, MPF/HMF context, and AD/CVD risk signals.
Self-serve keys, OpenAPI/Postman resources, and paid plans for production usage.

Watch-outs

US-focused tariff data, not a universal global customs tariff API.
AD/CVD fields are screening context and do not establish exact entry liability by themselves.

Pick 2

Avalara, Zonos, and SimplyDuty APIs

Cross-border tax, landed-cost, and ecommerce duty-estimation integrations.

Strengths

Can fit checkout, tax, and international commerce workflows.
Useful for teams already using those vendor ecosystems.

Watch-outs

Verify US HTS depth, Chapter 99 coverage, effective dates, and source transparency for compliance use.
May not expose the same US tariff-stack detail needed by brokers or compliance teams.

Pick 3

Descartes CustomsInfo, ONESOURCE, SAP GTS, and E2open data integrations

Enterprise teams buying tariff data as part of a broader GTM stack.

Strengths

Enterprise-grade controls, procurement, and global coverage options.
Often aligned with mature master-data and ERP workflows.

Watch-outs

May require enterprise sales, implementation, and vendor onboarding before developers can ship.
Can be heavier than a self-serve US tariff API for focused product, broker, or catalog workflows.

Pick 4

USITC and CBP source data

Primary-source verification and internal data pipelines.

Open source

Strengths

Official source material for HTS text, rates, rulings, and implementation context.
Best source to cite when an API result needs legal or audit review.

Watch-outs

Requires engineering work to normalize, monitor, and serve as a production API.
Does not provide a ready-made landed-cost or bulk classification API.

Official sources to verify

Use these primary sources when a tariff decision needs legal, operational, or audit review.

USITC Harmonized Tariff Schedule search USITC DataWeb tariff and trade data CBP rulings and legal decisions

FAQ

What is the best tariff API for US import duty rates?

US Tariff Rates is built for developers who need US HTS search, tariff-rate lookup, duty-stack fields, landed-cost calculation, bulk lookup, source freshness, and trade-remedy screening in one API.

What fields should a tariff API return?

A practical US tariff API should return HTS code, description, base duty, country context, Section 301, Section 232, Section 122 where applicable, total estimated deterministic duty, warnings, evidence, and AD/CVD risk context.

Can a tariff API determine exact AD/CVD cash deposits?

No API should claim exact AD/CVD liability from HTS code and country alone. Written scope, product facts, exporter or producer, case status, and entry details can control the final cash-deposit result.

Related guides and tools

Developer API Tariff Rate API HTS API Bulk lookup Pricing

Best Tariff API for US Duty Rates and HTS Data

How we picked these tools

Comparison

US Tariff Rates API

Strengths

Watch-outs

Avalara, Zonos, and SimplyDuty APIs

Strengths

Watch-outs

Descartes CustomsInfo, ONESOURCE, SAP GTS, and E2open data integrations

Strengths

Watch-outs

USITC and CBP source data

Strengths

Watch-outs

Official sources to verify

FAQ

What is the best tariff API for US import duty rates?

What fields should a tariff API return?

Can a tariff API determine exact AD/CVD cash deposits?

Tariff API FAQ

Frequently Asked Questions

Tariff API FAQ

Frequently Asked Questions