What is ISIC Revision 4?

ISIC Revision 4 was the version of ISIC in use since 2008 (FIXED, as stated in the United Nations Statistics Division account of ISIC Rev. 5), and it was the version from which NACE Rev. 2 was derived. ISIC Rev. 5 now replaces the fourth version as the internationally accepted standard for economic activities, in the words of the introduction to ISIC Rev. 5 published by the United Nations Statistics Division. ISIC Rev. 4 therefore remains important for two reasons: it is the basis of NACE Rev.

2 and of the national classifications derived from it, and it is the version used in many datasets that have not yet moved to Rev. 5. A dataset that uses ISIC Rev. 4 is not out of date in a careless sense. It is on a named version, and it must be read on that version.

What was the position of ISIC Rev. 4?

ISIC Rev. 4 was the fourth revision of ISIC, adopted after the revisions of 1958 (FIXED), 1968 (FIXED), 1989 (FIXED) and 2002 (FIXED), in the chronology given in the United Nations Statistics Division classification detail for ISIC Rev. 5. The original version was adopted in 1948 (FIXED). Each revision reflected changes in the world economy since the previous one, and each revision required national classifications derived from ISIC to be reviewed in turn. ISIC Rev. 4 was in use for a long period, from 2008 (FIXED) until the endorsement of Rev. 5, and during that period it became the reference for a large body of statistics, code lists, and national versions. The length of its use is itself a reason to record the version carefully: a code, a table, or a dataset from that period is a Rev. 4 record, and it should be cited as such, even where the same code string appears in Rev. 5 with a different meaning.

How does ISIC Rev. 4 relate to NACE Rev. 2?

NACE Rev. 2 was derived from ISIC Rev. 4, on the same pattern as NACE Rev. 2.1 is derived from the ISIC system. Eurostat states in its NACE background article that NACE is derived from ISIC, in the sense that it is more detailed than ISIC, that ISIC and NACE have exactly the same items at the highest levels, and that NACE is typically more detailed at lower levels. The Central Statistics Office states the same relationship in the same terms. For the Rev. 2 period, that meant that a NACE division matched an ISIC division at the highest levels, while the groups and classes below it carried European detail. A reader who compares a NACE Rev. 2 figure with an ISIC Rev. 4 figure should compare at the level where the two classifications match, and should check the correspondence table before comparing at a lower level, where NACE detail has no direct ISIC equivalent.

Why do datasets still use ISIC Rev. 4?

Datasets still use ISIC Rev. 4 because classifications change on a timetable, and because historical series are compiled on the version in use when the reference period was produced. The United Nations Statistics Division states that the ISIC Rev. 5 publication is currently undergoing copyediting and preparation for publication, and that the final version will be provided when available. National classifications and business registers move to a new ISIC revision on their own timetables, and datasets follow the classification version of the register and the production cycle behind them. A dataset that uses ISIC Rev. 4 therefore does not need to be corrected by a reader. It needs to be cited with its version, its reference period, and any note about a planned move to Rev. 5, so that a comparison with a Rev. 5 dataset is made knowingly, with the correspondence between the revisions consulted.

Revision	Position, as stated by the United Nations Statistics Division
ISIC, original version	Adopted in 1948 (FIXED)
ISIC Rev. 4	In use since 2008 (FIXED), replaced as the standard by Rev. 5
ISIC Rev. 5	Structure endorsed in March 2023 (FIXED), replaces Rev. 4 as the standard
NACE Rev. 2	Derived from ISIC Rev. 4, on the pattern stated by Eurostat

The table keeps the two classifications in separate rows. A row for ISIC is not a row for NACE, and a date for one is not a date for the other. The relationship is derivation, not identity, and the table shows derivation without collapsing the two histories into one.

How is a Rev. 4 code checked?

A Rev. 4 code is checked in the Rev. 4 publication, not in the Rev. 5 publication. The United Nations Statistics Division provides previous versions of ISIC on its ISIC page, under the heading for previous versions. A reader should open the Rev. 4 structure and explanatory notes, confirm the category title and the inclusions and exclusions for the class, and record the version in the citation. Where the code is compared with a Rev. 5 code, the correspondence between the revisions should be consulted, and the mapping type should be recorded, because a Rev. 4 class can split, merge, or move in Rev. 5, and the mapping does not guarantee a one to one result. Where the code is compared with a NACE code, the correspondence between ISIC and NACE should be consulted at the level where the two match.

What does ISIC Rev. 4 not decide?

ISIC Rev. 4 does not determine the code for any reader, and it does not decide tax, licensing, funding, collective agreement or social security questions. It is a statistical classification, and a code on that basis describes an activity category for statistics. The entry for a specific business is confirmed, in the register classification version, with the national statistical institute or the business register holding the record. The meaning of a Rev. 4 category is confirmed in the Rev. 4 publication of the United Nations Statistics Division.

Open the Rev. 4 publication for a Rev. 4 code, record the version with every citation, and confirm a business entry with the institute or register that holds it. ”