What is the overall change in numbers?

The overall change in numbers is a net change: from 21 sections, 88 divisions, 272 groups and 615 classes in NACE Rev. 2, to 22 sections, 87 divisions, 287 groups and 651 classes in NACE Rev. 2.1. The differences are plus 1 section, minus 1 division, plus 15 groups, and plus 36 classes. The table is a summary of the adopted structures. It does not list every category that was created, removed, split, merged, or renamed, and it must not be read as if it did.

How does the manual explain each row?

The manual explains each row beside Table 5. The increase in sections is caused by the split of the former Section J into two sections, and is presented in the first row. The smaller number of divisions results from the suppression of the former division 45, and is shown in the second row. The differences in groups and classes result from the net difference between the number of new categories created in NACE Rev. 2.1 and the number of categories from NACE Rev. 2 that have been removed. The explanation therefore separates the structural causes, the section split and the division suppression, from the net arithmetic at group and class level, where many movements combine into one net figure.

Eurostat states on its overview page that NACE Rev. 2.1 introduces new concepts at all levels and restructures a number of existing headings, while efforts were made to maintain the structure in all areas that did not explicitly require change based on new concepts. That statement matches the net figures: change at every level, but not change everywhere. Much of the classification is unchanged, and the net increase of 36 classes sits inside a structure of 651 classes, most of which continue from the earlier version in some form. The correspondence type figures show the scale more precisely, and they are covered in the correspondence tables cluster.

Level	NACE Rev. 2	NACE Rev. 2.1	Difference
Sections	21	22	Plus 1
Divisions	88	87	Minus 1
Groups	272	287	Plus 15
Classes	615	651	Plus 36

Why must the two sets of counts never be mixed?

The two sets of counts must never be mixed because they describe two different adopted structures. The Rev. 2 counts describe the structure published in 2006 (FIXED), used for European statistics referring to the period from 2008 to 2024 (FIXED range). The Rev. 2.1 counts describe the structure specified by the delegated regulation dated 10 October 2022 (FIXED), to be used for European statistics from 2025 (FIXED) onwards. A statement that NACE has 21 sections and 651 classes, or 22 sections and 615 classes, mixes the two structures and states a structure that was never adopted. A statement that NACE has 88 divisions and 287 groups mixes them in the same way. Every count in a guide on this site must therefore be labelled with its version, and the version must be checked against Table 5 before the count is used.

Mixing counts is easy when a summary gives only one figure, or when a national version is counted. A national version usually adds a fifth digit, according to the manual, and a count of national categories will be larger than the European class count. A count from a draft, or from a structure table for a different edition, may also differ. The check is simple: compare the count with Table 5, confirm the version, and confirm the level counted. If any of those three does not match, the count must not be used as an adopted count for that version and level.

What does the net change hide?

The net change hides the gross movements. At class level, the net increase of 36 is the result of creations minus removals, after splits and mergers have been accounted for. A split creates more than one new class from one old class, and increases the count. A merger removes more than one old class into one new class, and decreases the count. A restructuring can create and remove categories at the same time, with a small net effect and a large detailed effect. The manual section on major changes lists splits, mergers, restructurings, creations, and moves at group and class level, and the correspondence tables give the detailed relationship for each class. A reader who needs to know what happened to a particular class must read those sources, not Table 5.

The net change also hides heading changes that do not change the count. The manual states that minor changes, not listed in the major changes section, include heading changes at group and class level, renumbering, recoding, and partial transfers of content between classes. A class can therefore keep its place in the count while its heading, its number, or part of its content changes. Table 5 will show no change for that class, because the count is unchanged, while the correspondence table and the notes will show the change in detail. The count is a summary of structure, not a record of content.

What does the change in numbers not decide?

The change in numbers does not decide the new class for a business, and it does not decide whether a register entry has changed. A net increase of 36 classes does not mean that every business gains a new code, and a decrease of one division does not mean that every business in that division moves. Each class move is recorded in the correspondence table, with a type that states whether the relationship is one to one, many to one, one to many, or many to many. The explanatory notes for the new classes state what each new class includes and excludes. The institute or register that holds the record confirms an entry, using those sources and the information held about the unit.

Check Table 5 for the adopted counts for each version, check the correspondence table for the move of a particular class, and confirm any entry with the national statistical institute or the business register that holds the record.