PlainTariff turns two public datasets — the U.S. International Trade Commission's Harmonized Tariff Schedule (HTS) and the FAO FAOSTAT agricultural trade database — into searchable, plain-language pages for every HTS chapter, section, heading, commodity, and trading country. This page explains how those pages are produced, what standards they are held to, how derived figures are computed, and how to report a number that looks wrong so we can fix it at the source.

How these pages are produced

Every duty rate, tariff-line count, average, and trade value on PlainTariff originates in an official public record. We ingest the USITC HTS Basic Edition for classifications and duty rates, and the FAO FAOSTAT Trade: Crops and Livestock (TCL) dataset for agricultural import and export flows, load everything through a documented, version-controlled data pipeline, and render it into chapter, section, heading, commodity, country, ranking, and guide pages using shared templates. No data page is hand-written and no duty rate is typed in by an editor — each figure you see is read directly from the source record at build time, so the same number is consistent wherever it appears.

Our editorial identity is responsible for the parts a pipeline cannot decide on its own: which datasets to use, how each measure is defined and labeled, how derived figures (averages, distributions, rankings) are computed — see our methodology — which guides we write, and what we will not publish. The pipeline then applies those decisions uniformly across every page, so the rule that governs one chapter page governs all of them.

How derived figures are computed

Most numbers on PlainTariff are reported directly from the source (a line's general rate, a chapter's tariff-line count). Where a figure is derived, we compute it transparently from the same source data. An "average dutiable rate," for example, is the mean general (MFN) rate among lines that actually carry a duty — it excludes the thousands of duty-free lines, which would otherwise pull the average down and misrepresent what dutiable goods face. We label the denominator wherever a derived rate appears, because the choice of denominator changes the result. Rankings surface a single reproducible metric and link to the underlying records so you can verify the order yourself.

Sourcing standards

We publish only data that comes from official public sources, and we name the source on every page:

• USITC Harmonized Tariff Schedule (HTS): the U.S. International Trade Commission's official classification system and duty-rate schedule for goods imported into the United States — the source for every chapter, section, heading, and duty rate on the site. Verify any rate at hts.usitc.gov.
• FAO FAOSTAT (Trade: Crops and Livestock): the Food and Agriculture Organization of the United Nations' database of international agricultural trade flows, used for the commodity and trading-country pages. Values are converted from FAO's 1,000-USD reporting units to USD.

We do not scrape third-party sites, we do not republish self-reported figures as our own, and we do not assign tariff determinations on top of the published schedule. Where a figure is derived from the official data, the page links to our methodology, which sets out exactly how it is calculated.

Accuracy and validation

Because the numbers are read straight from the USITC and FAO files, the most common limitation is the underlying record or its vintage rather than a transcription error. Tariff rates change between USITC revisions and through trade-policy actions (Section 301, Section 232, anti-dumping and countervailing duties), and FAO trade data typically lags one to two years behind the calendar date. Our pipeline shows a value as unavailable when the source omits it, never infers a rate that is not published, and reconciles chapter, section, and national rollups so the same figure is consistent everywhere.

When we find that a displayed number is wrong, we fix the cause, not the symptom. We trace the value back to the data layer, correct the derivation or labeling rule there, and regenerate the affected pages, so the same class of error is resolved everywhere at once rather than patched on a single page.

Editorial independence

PlainTariff does not accept payment, sponsorship, or promoted placement from importers, exporters, customs brokers, or any organization in exchange for how data is presented or ordered. Our only revenue source is contextual display advertising. Advertisers have no influence over which data we publish, how a rate is reported, or how any page ranks.

Update schedule

The USITC publishes a new HTS Basic Edition annually, with mid-year revisions for trade-policy actions, and the FAO releases new annual trade figures on its own cadence. We refresh our database from the latest official exports and re-stamp the affected pages so the published date reflects when the data genuinely changed, not when the page was last rebuilt.

Corrections process

If a figure looks wrong, please tell us. We treat data-error reports as a priority and follow the same process every time:

1. Report. Email hello@plaintariff.com with the page URL and the figure you are questioning.
2. Verify. We check the value against the official USITC HTS or FAO FAOSTAT record, using the HTS code or commodity identifier.
3. Fix at the source. If the figure is wrong on our side, we correct the underlying data or derivation rule and regenerate every page it affects.
4. Note it. If the figure is correct but reflects a known limitation — a rate changed by a recent trade action, or FAO data that lags the current year — we explain the caveat rather than silently changing it.

Some apparent errors trace back to the official record itself. When that is the case, we will tell you so and point you to hts.usitc.gov so you can verify the current rate directly.

Contact

Questions about our standards, methodology, or a specific figure are welcome at hello@plaintariff.com. For more on what the data covers and how it is processed, see our About page and methodology. For how to use this information responsibly when making import decisions, see our disclaimer.