537 Harmonized System Codes and Other Classification Codes

537.1 Definition

The Harmonized System (HS) codes provide a standardized numerical method of classifying physical goods. Among industry classification systems, HS codes are commonly used by customs authorities around the world to identify products when assessing duties and taxes and for gathering statistical information. When necessary, for each good contained in the mailed item, the applicable HS code must appear in the HS Tariff Number block on the customs declaration form.

537.2 Code Assignments

537.21 World Customs Organization Harmonized System

The World Customs Organization (WCO) administers the list of unique 6-digit HS codes for goods and provides updates every 5 years. HS codes serve as the foundation for the import and export classification systems for more than 200 countries worldwide, including the United States.

Each country is allowed to use additional unique digits following the 6-digit HS code for further classification — for example, the United States uses 10–digit codes for Harmonized Tariff Schedule (HTS) codes and Schedule B numbers.

Note: The last four digits of a U.S. 10-digit code do not necessarily match the last four digits for any other country.

537.22 U.S. Census Bureau Schedule B Number

The U.S. Census Bureau of the Commerce Department administers the list of Schedule B numbers. Schedule B numbers are 10-digit codes used to classify goods that will be exported from the United States. The first six digits of the Schedule B number match the WCO 6-digit HS code, whereas the last four digits are unique to the United States and do not necessarily match the last four digits of any other country’s 10-digit code.

537.23 U.S. International Trade Commission Harmonized Tariff Schedule of the United States

The U.S. International Trade Commission maintains and administers the list of HTS codes; however, U.S. Customs and Border Protection (CBP) has responsibilities for interpreting and enforcement. HTS codes are 10-digit codes used to classify goods and to determine import duty rates for items that will be imported into the United States. The first six digits of the HTS code match the WCO 6-digit HS code, whereas the last four digits are unique to the United States and do not necessarily match the last four digits of any other country’s 10-digit code.

537.3 Obtaining a Harmonized System Code

Some customs authorities around the world require a mailer to include the HS code on the customs declaration form. See the Individual Country Listings. A mailer may choose from a variety of software tools to facilitate the classification process, but at all times, the mailer remains responsible for the accuracy and completeness of all customs information related to the mail, including information for classification of goods in the postal items.

537.31 Code Search Tools

A variety of tools are available to mailers, including the following examples (which are subject to change):

  1. The Census Bureau offers a free, widely used online Schedule B search tool for classification of physical goods. Additional information on obtaining a Schedule B number is available at https://uscensus.prod.3ceonline.com.
  2. The International Trade Commission offers a free online HTS search tool for classification of physical goods. Additional information on obtaining an HTS code is available at https://hts.usitc.gov/search.
  3. The Customs Rulings Online Search System (CROSS) contains many of the CBP’s official, legally binding rulings from other importers’ and exporters’ requests concerning HTS codes and Schedule B numbers. Mailers may use this database to determine whether other importers or exporters requested a ruling on the same or a similar product and, if so, what that ruling was. Additional information is available at https://rulings.cbp.gov/home.
537.32 U.S. Schedule B and HTS Lists

Mailers may browse through the contents of the online Schedule B book at https://www.census.gov/foreign-trade/schedules/b/index.html.

Mailers may browse through the contents of the online Harmonized Tariff System of the United States (HTSUS) at https://www.usitc.gov/harmonized_tariff_information.

537.4 Mailer Responsibility for HS Code Classification

A mailer may elect to use any USPS classification software or other tools to determine HS codes, or may choose to use other software or other means to determine correct HS codes. Regardless of the method used, the mailer remains solely responsible for the accuracy and completeness of all customs information related to the mail, including the accuracy of HS codes that correspond to the detailed descriptions of goods. The Postal Service is not liable for any of the following:

  1. Any incorrect or insufficient HS, HTS, or Schedule B classification.
  2. Any other incorrect or incomplete information for customs declarations in whatever form such information is made.
  3. Any decision taken by any domestic or foreign customs authority.