A harmonized code, or HS code, is the number that tells customs exactly what a shipment contains, independent of who sent it or what it cost. The system behind it is the Harmonized System: a six-digit international standard that sorts every kind of physical good into a chapter, a heading and a subheading. Countries extend those six digits for their own tariff and export rules, which is why a US shipment carries a ten-digit code rather than a six-digit one. The number decides duty rates and customs paperwork; it has nothing to do with the domestic price of getting a box to the carrier.
Six digits are shared everywhere the Harmonized System is used. The four after that depend on which direction the box is moving.
The Harmonized System is maintained by the World Customs Organization, which revises it on a five-year cycle, per trade.gov, read 2026-08-22. Its structure has three layers, and the layers are set by digit count alone, per the European Commission's Access2Markets glossary, also read 2026-08-22: a chapter runs the first two digits, a heading the first four, and a subheading the full six. Their own worked example is grain rather than a parcel: chapter 10 is cereals, heading 10.06 narrows that to rice, and subheading 1006.30 narrows it again to semi-milled or wholly milled rice. The same three-layer split applies to every chapter, from live animals to machinery.
Six digits is where the international standard stops. A country wanting finer detail adds its own digits on top of that, and the United States adds four: a ten-digit number for both imports and exports, with the first six held in common between them, per trade.gov, read 2026-08-22. Which ten-digit list applies depends on which way the box is moving.
Kept by the US Census Bureau. Read 2026-08-22, the Bureau describes it as the schedule of commodity classifications a shipper uses to report an export from the United States, and the source of the export statistics it publishes. A seller shipping goods out of the country files this one.
Kept by the US International Trade Commission. A good imported for resale is classified under the Harmonized Tariff Schedule instead, and that classification is what sets the duty owed at the border.
Both numbers open with the same Harmonized System subheading, so a product correctly matched to one is matched to the same six digits in the other. Only the last four, and the specific commodity list a country keeps beyond that, can diverge.
Our auto parts HS code guide works through one Schedule B heading, 8708, parts and accessories of motor vehicles, subheading by subheading, if seeing a full heading laid out end to end is useful before you search for your own.
Not on this site, and not on any move that stays inside the country. A classification number is a customs concept: it sets a duty rate and clears a border. A parcel that never crosses one has no duty to set and nothing for a classification to touch. Two boxes captured through the SMKlog calculator on 2026-08-22, same lane, same carrier, same service, show the point directly.
| Box | Schedule B chapter it would carry if exported | Weight | Price |
|---|---|---|---|
| Wireless earbuds and phone chargers, 12 x 10 x 6 in | Ch. 85 | 4 lb | $14.70 |
| Cotton t-shirts, 16 x 12 x 10 in | Ch. 61 | 8 lb | $30.80 |
Chapter 85 and chapter 61 are not neighbors. Read 2026-08-22, the Census Bureau's 2026 Schedule B lists chapter 85 as electrical machinery and equipment and chapter 61 as apparel and clothing accessories, knitted or crocheted. None of that distance shows up in what separates the two rows above. What moved the price was four extra pounds and a larger box on the same lane, the two inputs a domestic parcel rate has always used. If either box were headed out of the country instead, its chapter would decide the duty on that leg and the paperwork that comes with it, priced through an entirely different system from anything shown here.
SMKlog's checkout prices US domestic parcel labels and nothing past the border: no customs paperwork of any kind comes out of it, and no number on this page reflects what happens once a shipment leaves the country.
A classification is chosen by what the item physically is, never by its price, its buyer, or the reason it is being sent. The same shirt gets the same chapter whether it travels as a single gift or a wholesale pallet.
Most chapters carry a residual subheading at the end for goods that fit nothing named above it. Reaching for that leftover line when a specific one already covers the item is the shortcut that draws the closest look at a border.
The Census Bureau's Schedule B search tool takes a plain description and returns candidate codes with their full text. Two subheadings a few digits apart can describe very different goods, so the wording is what actually confirms a match.
The Harmonized System and the schedules built on it are revised on their own timetables. Treat the figures above as what these sources published on the date shown, and confirm the current edition before filing anything against it.
Short for Harmonized System code: a six-digit international standard, maintained by the World Customs Organization, that classifies a physical good by what it is rather than by its price or its buyer. The United States extends it to ten digits for both imports and exports, keeping the first six the same either way.
Digit count. A chapter is the first two digits and sets the broad category, a heading is the first four and narrows that to a product family, and a subheading is the full six and narrows it once more. The European Commission's own example: chapter 10 is cereals, heading 10.06 is rice, and subheading 1006.30 is semi-milled or wholly milled rice.
The first six digits are, because both are built on the same Harmonized System. The last four are not: Schedule B is the Census Bureau's numbering for what leaves the United States, and the Harmonized Tariff Schedule is the US International Trade Commission's numbering for what enters it. A seller shipping goods out of the country files Schedule B.
No. Our checkout prices a domestic parcel by its weight, its dimensions and the ZIP pair it is moving between, the same inputs every domestic carrier rate uses. Classification only enters the picture once a box crosses a border, and pricing that leg is not something this site does.