Trimtabist
The independent record of what US trade rules required and what importers were actually billed — and a free check of any customs entry you have filed against it.

How a line is priced

Two numbers sit on every line and they are not the same kind of thing. One was counted by somebody else. The other we built by reading the schedule. This page is how the second one is built, and what happens on the lines where it cannot be built at all.

The arithmetic, in the order it is applied

the rate the schedule required =
  Column 1 General rate (the ordinary base rate)
+ Section 232   + Section 301   + IEEPA
+ the country measure under Chapter 99   + Section 122

Every term is read at the entry’s own month and origin, not at today’s. That is the whole difficulty: a line entered in April 2025 and the identical line entered in June 2026 are governed by different law, and a lookup tool that reads today’s schedule gets the first one wrong. The Section 232 carve-out is applied where it belongs, so a product that merely contains the metal (a “derivative article”) is not charged twice on its metal content.

The schedule we read
2026HTSRev18 · 29,860 lines
Chapter 99 measures mapped
600, across 75,504 code entries, each traced to its Federal Register document
Lines priced this way
1,290,386 — 16,513 ten-digit codes × 10 origins × every month from January 2024 to June 2026
The other number
Duty assessed at entry ÷ dutiable value, counted by US Census. 19,850,923 measured lines, January 2017 onward. Nothing built on top of it.
Which is which, always
One of the two numbers on every line was counted by a named body. The other we built by reading law. We never quote the second as though somebody measured it, and we never mix the two silently.

Scope, because it is not national
Canada, China, Germany, India, Japan, Mexico, South Korea, Taiwan, Thailand, Vietnam — and only the lines Chapter 99 reaches. Any figure from the book we built is an in-scope figure and is labelled one.

What “could not be priced” means

This is the part worth arguing with, so it is stated in full rather than softened. On 268,617 of 1,290,386 lines — 20.8% — the public record does not settle the rate. Not because the data is missing: because the rule turns on a fact that only the filed entry declares. Those lines get an interval — the lowest and highest rate the rule could produce — and a named reason, and they are not dropped.

A count of lines and a share of money are different claims, so here is the second one too. In June 2026 those lines carry $26.47bn of the $81.29bn of dutiable value we can see — 32.6%. The share of money is the larger of the two, and it is the one printed wherever a page has room for only one.

why the rate cannot be settled from public recordslines
per-entry declaration not carried by monthly receipts250,240
metal share of article WEIGHT, U.S. note 16(c): outside ch.72/73/74/76 the heading applies only at >=15%8,471
USTR exclusion claim, U.S. note 20(dd)/(vvv): relief applies only where the importer entered under the exclusion heading3,940
USMCA non-US-content share, 9903.94.03 / U.S. note 33(d)3,141
metal share of article WEIGHT, U.S. note 16(c): outside ch.72/73/74/76 the heading applies only at >=15% + US-melted-and-poured share, U.S. note 16(e)/(f); 9903.82.07/.08 at 10% vs 9903.82.10/.11 at 15%2,764
enteral-syringe carve-out 9903.91.10; scope not enumerated61
Settled from the public record1,021,769

Dropping them would be the easy move and it would flatter us: a smaller denominator makes the remaining agreement look tighter than it is. They stay. A count of lines we could not price cannot be wrong — which is why it is the more defensible half of what we publish, and why it is printed in the same typography as the lines that agree.

It is also the reason the check asks for your document. Your own entry is the only thing that resolves a line like this: it is the form that declares the metal share, the exclusion, or the US content.

How a rate for a whole era is put together

A rate for one line is a division. A rate for a country, a chapter or an era is an index number — and an index number is not just a bigger division. Three choices sit inside it, each defensible, each moving the answer. We publish all three rather than leave a reader to guess.

What goes underneath Value that owed duty. Dividing by all import value instead gives a number less than half as large for the same month.
Which period is the yardstick 2024, unchained. About 2.7 points move across four defensible choices of base.
How finely the data is cut Origin and six-digit code — the finest the ledger supports. Cutting by origin alone moves the answer about 1.2 points.

The plain average of a rate across an era uses that era’s own import mix. That is the right answer to “what was charged on what actually arrived”, and the wrong answer to “what did the rulebook cost”. When a tariff rises, imports move away from what it hits, so the later average is taken on a basket that has already dodged part of the increase. On this ledger that understates a fixed basket by roughly 16% cutting by origin and 30% cutting by origin and product.

So we publish a Fisher index beside it — the same comparison run on the old basket and on the new one, then combined. It is superlative: the price part and the quantity part separate exactly, rather than by a convention someone picked. We do not publish its usual companion, a Törnqvist index: 2024 rates sit near zero for many cells because those tariffs did not exist yet, and an index built on log changes is unstable against a near-zero base. Tested here, it fell outside the bracket its own two halves define, which disqualifies it.

Falsify it

Two breaks in the record, both real

April and May 2025 are 100% unpriceable on China : the required rate moved 34% → 84% → 125% → 10% inside two months, and monthly receipts cannot say which one a given entry met. That is a real property of that window, not a gap in our data collection.

A second break at April 2026, as the Proc. 11021 metal tiers and the USMCA content band take effect. A chart drawn straight across either of those points is drawing a line through a change of law.

Send one entry

The arithmetic above is what runs on a real entry, line by line, at each line’s own date and origin — including the lines it refuses to price.

Check one of your own entries

Free. No account. We do not file with CBP and take no fee on anything you recover. Your file is read on our own server and is never sold or shared.

try it on one code · the national number · the test we failed, and the conflict · what we got wrong