Tandom · Duty calculator
Add country and invoice value for the full duty stack — base + 301 + 232 + AD/CVD + fees.
HTS 2528.00.00.50 is the U.S. Harmonized Tariff Schedule classification for Natural borates and concentrates thereof (whether or not calcined), but not including borates separated from natural brine; natural boric acid containing not more than 85 percent of H3BO3 calculated on the dry weight, other. It's a 10-digit statistical line in Chapter 25: Salt; sulfur; earths and stone; plastering materials, lime and cement, Section V: Mineral Products, used by U.S. Customs and Border Protection to determine the duty rate at entry. No Chapter 99 tariff modifications (Section 301, Section 232, IEEPA) or AD/CVD orders currently flag this code in Tandom's catalog.
New to HTS codes? Read our guide on how HTS classification works →
HTS 2528.00.00.50 is the U.S. Harmonized Tariff Schedule classification for Natural borates and concentrates thereof (whether or not calcined), but not including borates separated from natural brine; natural boric acid containing not more than 85 percent of H3BO3 calculated on the dry weight, other. It belongs to Chapter 25 of the HTSUS.
The general (Column 1) duty rate for HTS 2528.00.00.50 is Free. This is the most-favored-nation (MFN) rate that applies to imports from World Trade Organization member countries.
No active Chapter 99 tariff overlays (Section 301, Section 232, IEEPA reciprocal, etc.) currently flag HTS 2528.00.00.50 in Tandom's catalog. Use the calculator's date + origin inputs to confirm against any retroactive overlay you may be filing.
No active AD/CVD orders currently flag HTS 2528.00.00.50 in Tandom's catalog. Tandom monitors Federal Register notices daily; a flag will appear here within 24h of any new order's publication.
Tandom guides relevant to this code
Where trade compliance APIs fit in a broker's filing pipeline: HTS classification, duty calculation, AD/CVD scope match, and post-summary corrections.
Open resource
Run thousands of product descriptions through HTS classification, score the confidence, and triage borderline rows. Public search endpoint plus the closed-beta three-layer Classifier.
Open resource
How to read, order, and report Chapter 99 HTS codes alongside the base classification on a US entry summary in 2026. The full stacking ladder for brokers and compliance teams.
Open resource
Why raw LLM prompts fabricate stat suffixes, why MCP-augmented prompts do not, and the prompt template a broker can hand to Claude or ChatGPT today.
Open resource
What changed for low-value DTC and ecommerce shipments after Section 321 de minimis was suspended in 2025. Filing, fees, and duty math through 2027.
Open resource
Turn a PDF commercial invoice into ACE-ready entry data. Which fields to extract, how to chain extraction into HTS classification and duty calculation.
Open resource