Data Sources & Methodology

Complete transparency on where our tariff intelligence comes from

Official Government Data Sources

BASE

U.S. International Trade Commission (USITC)

Harmonized Tariff Schedule of the United States (HTSUS) - The official source for all base MFN (Most Favored Nation) tariff rates and HS code classifications.

Update Frequency: Annual (January 1)
Coverage: 18,500+ HS codes
Data Type: MFN rates, USMCA rates, descriptions
Authority: 19 U.S.C. § 1202
View Official HTS →
301

Federal Register - USTR Section 301

Section 301 tariffs on Chinese imports, published by the Office of the United States Trade Representative. These are the "China trade war" tariffs ranging from 7.5% to 25%.

Update Frequency: Daily automated sync
Coverage: 6,500+ HS codes
Rate Range: 7.5% - 25%
Legal Basis: Trade Act of 1974 § 301
View USTR Actions →
232

Federal Register - Commerce Section 232

National security tariffs on steel (25%), aluminum (25%), and copper (50%) imports. Published by the Department of Commerce under presidential proclamation.

Update Frequency: Daily automated sync
Coverage: 880+ HS codes
Rate Range: 25% - 50%
Legal Basis: Trade Expansion Act § 232
View Commerce Actions →
IEEPA

Federal Register - IEEPA Reciprocal Tariffs

Reciprocal tariffs imposed under the International Emergency Economic Powers Act. Currently 10% on all Chinese imports effective May 14, 2025.

Update Frequency: Daily automated sync
Coverage: 9,300+ HS codes
Current Rate: 10% (China)
Legal Basis: 50 U.S.C. § 1701 (IEEPA)
View CBP Guidance →

Automated Sync Methodology

Triangle automatically monitors official government sources and updates tariff rates daily. Here's how our sync process works:

Daily at 06:00 UTC: Federal Register API is queried for new USTR, Commerce, and CBP notices about tariff modifications.
  1. Search Federal Register API - Query for USTR (Section 301), Commerce (Section 232), and Executive Office (IEEPA) documents from the past 90 days
  2. Parse Official XML - Extract HS codes and tariff rates directly from Federal Register XML tables (no AI interpretation for rates)
  3. Update Database - Upsert new rates to policy_tariffs_cache with source attribution and verification timestamps
  4. Log & Verify - Record sync results to audit log, flag any stale records for review
30-Day Notice Rule: Federal law requires at least 30 days notice before tariff rate changes take effect. Our daily sync ensures you always have current rates before they become effective.

Why Trust Triangle

100%
Government Sources

No third-party data. Every rate comes from official Federal Register or USITC sources.

Daily
Automated Updates

Federal Register is monitored every day at 06:00 UTC. No manual updates to forget.

Full
Audit Trail

Every rate includes source URL, verification date, and Federal Register document number.

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Questions about our data sources? Contact support@triangleintelligence.com