Concordance between NAICS United States 2002 and ISIC Rev. 3.1

Over a course of twenty-four months, a working group including Eurostat, Instituto Nacional de Estadística, Geografía e Informática (INEGI), Statistics Canada, the United Nations Statistics Division (UNSD), and the United States Economic Classification Policy Committee (ECPC), developed concordances among the North American Industry Classification System (NAICS United States 2002), the Statistical Classification of Economic Activities in the European Union (NACE Rev. 1.1), and the International Standard Industrial Classification of All Economic Activities (ISIC Rev. 3.1). New versions of these classifications were introduced in 2002 and this work represents the first comprehensive review of their similarities and differences.

There is significant interest in being able to compare industrial statistics presented using a variety of international, regional, and national classifications. Concordances provide a valuable tool for comparing North American industrial statistics with the industrial statistics of a large number of nations whose systems are based on ISIC or NACE.

These concordances were developed as part of a larger study on improving the comparability of industrial classifications in Europe and North America. This project, often referred to as the convergence study, began in June 2000. At the UN Statistical Commission meeting in 2002, the terms of reference for the project were modified to expand its scope. In addition to being an exercise between North America and Europe, it was agreed the project would provide input to the scheduled revision of ISIC in 2007. The concordances were a necessary first step in comparing and contrasting ISIC, NACE, and NAICS in order to assess the feasibility of achieving greater comparability among these classifications.

This effort is unique in that the custodians of each of the classifications were directly involved with the assignment of codes for their systems. The result is concordances that have been validated by their custodians.

A variety of tools and reference materials were used to develop the concordances. Primary were the detailed industrial classification manuals, index item or activity lists, interpretations and rulings, and other descriptive materials. The United States ECPC generated the initial working comparisons between NAICS and NACE. The results were refined and validated through a series of face-to-face meetings, e-mails, phone calls, and a considerable amount of research. When the working concordance between NAICS and NACE was complete, in draft, the Statistical Classifications Section of UNSD applied ISIC codes to the concordance. This required some additional modifications to ensure that a unique link existed when all three classifications were considered.

The concordances are dynamic and will be updated for new interpretations and other changes arising through broader use.

The United States will post the concordances on the NAICS website at Questions on the NAICS United States' versions of the concordances can be directed to John Murphy, Chair, Economic Classification Policy Committee, by e-mail at

Eurostat will post the concordances on the ramon classifications server at Questions on NACE can be directed to Mr. Niels Langkjaer by e-mail at

The United Nations Statistics Division will post the concordances on their website at Questions on ISIC can be directed to Ralf Becker, Chief, Statistical Classifications Section, through the Classifications Hotline e-mail at

Canada and Mexico are nearing completion of their national NAICS concordances and will be posting them as well. Reports of the convergence working group and links to the other participants are available at:

Last release: 1 October 2003.