Duty and tariff calculation API for checkout.
One REST call returns the resolved duty rate for any HTS code and country of origin. USTR & CBP sourced, updated daily. Built for cross-border ecommerce, marketplaces, and ERPs.
From signup to first call
in under 10 minutes.
Every layer of the US tariff stack. One source of truth.
Harmonized Tariff Schedule
All 17,000+ 10-digit subheadings. Column 1 General, Column 1 Special (FTAs), Column 2.
China trade remedies
All four lists, exclusions, and product-specific notes. Effective dates tracked to the day.
Steel, aluminum, derivatives
Country-specific quotas and exemptions, including the 2025 Section 232 expansions.
Emergency tariffs
Country and product scope, refund-eligible periods flagged for CAPE and later rulings.
Modifiers & overrides
Every Chapter 99 subheading that layers on top, with stacking order respected.
Antidumping & countervailing
Active cases by producer and country, including cash deposit rates from the ITA.
The tariff API — one endpoint, deterministic JSON.
GET /api/v1/tariffs/resolve?hts=…&origin=… returns the base duty, every applicable Chapter 99 measure, a confidence score, and attempted candidates when the match isn't exact. Bulk endpoint accepts up to 200 codes per request. REST + JSON. No SDK required.
GET /api/v1/tariffs/resolve?hts=8541.10.00.80&origin=CN
// deterministic, no AI guessing
{
"hts": "8541.10.00.80",
"origin": "CN",
"match_type": "exact",
"match_level": "10",
"confidence": 1.0,
"base_duty": { "rate": "2.5%", "rate_type": "general" },
"additional_measures": [
{ "program": "Section 301", "rate": "25%", "chapter_99_ref": "9903.88.04" }
],
"warnings": [],
"attempted_candidates": []
}One plan. Everything in the API.
14-day free trial. Card required at signup, cancel any time before day 14 and pay nothing.
Everything you need to ship landed cost at checkout.
- ✓100,000 API calls per month
- ✓Single + bulk
/resolve(up to 200 HTS per request) - ✓Section 301, 232, IEEPA, Chapter 99 stacking
- ✓Historical rates with
as_of - ✓Confidence scores, warnings, match metadata
- ✓MCP server access
- ✓Priority support
Need higher volume or a custom SLA? Book a call.
Verified at every step.
Every rate we publish is pulled from official US trade publications, kept beside its raw source, audited by a separate AI pass, and re-tested before it ships. Traceable, audited, continuously tested.
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1Ingestion Pulled from source
Pulled directly from official publications. No spreadsheets. No scraping third-party sites. Every source row is preserved exactly as published.
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2Source archive Kept unchanged
Raw kept beside structured. Tagged to a numbered revision. We can reconstruct the rate on any past date.
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3Structured parse Made machine-readable
Raw duty text becomes structured rates. Every parsed value records how it was derived. Clean extractions stand apart from anything that needs review.
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4Independent audit Second pass, AI
A separate AI re-reads the source. Anything that does not match what we published gets flagged. Not the same system checking its own work.
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5Regression tests Caught before ship
Known lookups re-run on every update. Any failure is caught before it reaches a single customer.
Every rate is provable, audited, and continuously tested.
Stake a customs filing on it. We keep the receipts.
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May 28RegulatoryRegulatory Change: over-applying Section 122Shipped a fix for approximately 107k HTS codes in Chapters 84 and 85 that were previously over-applying the 15% Section 122 surcharge
You ask. We answer.
Can I calculate tariffs programmatically?
Yes. GET /api/v1/tariffs/resolve takes an HTS code and country of origin and returns the base duty plus every applicable Chapter 99 measure with rates, effective dates, and confidence scores. Bulk endpoint handles up to 200 codes per request. Pass as_of for historical rates. See /api-documentation.
Where does the data come from?
Every rate returned by Tariffs API comes from the official US Harmonized Tariff Schedule published by USITC, combined with USTR, CBP, and Federal Register notices for Section 301, 232, 122, and IEEPA measures. We never invent numbers.
How often is it updated?
Base HTS data is refreshed weekly against USITC's published schedule. Chapter 99 and trade-measure updates are captured daily from USTR and CBP notices. Breaking changes (new Section 301 rounds, IEEPA proclamations) are applied within 24 hours of publication.
Do you cover Section 301, Section 232, IEEPA, and reciprocal tariffs?
Yes. Section 301 (China), Section 232 (steel, aluminum, autos, semiconductors), Section 122 reciprocal duties, and IEEPA measures (including 2025 baseline, fentanyl-trafficking, Brazil/India-specific) are all resolved and stacked correctly on top of base HTS rates. Chapter 99 reference codes are resolved to numeric rates when available.
How does the 14-day free trial work?
Sign up with email and a card. You get full access to the API and every endpoint for 14 days. Cancel any time before day 14 and you're not charged. After day 14 the plan is $199/month. No long-term contract, cancel from the customer portal at any point.
What are the rate limits and infrastructure?
Pro is 500 requests per minute. Bulk /resolve handles up to 200 HTS per request with deduplication and caching, so a single bulk call counts as one API call against your monthly quota. Served from US-East on PostgreSQL with Redis caching. Enterprise customers get a contractual SLA.
How should I interpret the confidence score?
Every resolved measure includes a confidence score and a match type (exact, prefix, inherited). High confidence means the HTS code matched a measure directly. Medium or low means we inferred the match from a parent heading or a normalized variant — the JSON response includes attempted_candidates so you can verify. For anything low-confidence, cross-check with your broker or CBP.
Does Tariffs API replace a customs broker?
No. Tariffs API gives you accurate rate data and landed-cost calculations, but does not file entries, issue binding classification rulings, or act as a customs broker. Use it for checkout pricing, catalog pricing, compliance planning, and audit trails. Final classification and entry filing should go through a licensed customs broker.
Is this legal advice or a binding classification?
No. Data is for informational purposes. Final classification and duty determinations are made by US Customs and Border Protection (CBP). For binding rulings, request a CBP ruling letter. We tell you what the schedule says — CBP tells you what applies to your specific entry.
Ship landed cost at checkout this week.
Start your 14-day trial. Full access, all endpoints. Cancel before day 14 and pay nothing.
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