What is a merge in a correspondence table?

A merge in a correspondence table is a row pattern in which two or more Rev. 2 classes point to a single Rev. 2.1 class. The pattern shows that activities previously recorded under separate headings are now recorded under one heading for statistical purposes. It does not show that the activities became the same activity in the economy. It shows only that the classification now groups them together at class level. The table is the record of that grouping.

The explanatory note for the new class states what the combined heading includes and excludes, and that note is the place to check the scope before any entry is confirmed.

How is a merge shown in the table?

A correspondence table lists each Rev. 2 heading and, beside it, the Rev. 2.1 heading or headings to which its activities move. Eurostat states that the table describes, for each Rev. 2 heading, how activities currently classified therein should be classified in NACE Rev. 2.1. In a merge, several rows on the Rev. 2 side converge on one row on the Rev. 2.1 side. The direction matters. Reading from Rev. 2 to Rev. 2.1, the reader sees consolidation. Reading back from Rev. 2.1 to Rev. 2, the reader sees that the new class draws on more than one old class. Neither direction, on its own, describes a single business. The table is written for categories, not for individual units, and a category row cannot pick the class for a specific business.

Row pattern	Rev. 2 side	Rev. 2.1 side	What the row shows
Many to one	Two or more classes	One class	Activities grouped under one heading
One to one	One class	One class	Heading carried forward
One to many	One class	Two or more classes	Heading divided, a split
Many to many	Two or more classes	Two or more classes	Headings rearranged across the boundary

The table above is a record of row shapes, not a list of verified code moves. A row shape tells the reader what kind of check follows. A many to one row calls for a check of the combined explanatory note. A one to one row calls for a check that the title and the note still match the activity as described. No row shape is a guarantee about a particular entry.

What does a merge not prove?

A merge does not prove that two activities are now treated alike outside statistics. The EUR-Lex summary states that the legislation only applies to the use of the classification for statistical purposes, and that it does not oblige member states to collect, publish or supply data. A code does not grant a licence, set a tax rate, decide employment status, or decide eligibility for funding or a collective agreement. Those matters rest with the authority or register that holds the record, under its own rules. A merged class also does not prove that historical series can be read without a break. Where headings merge, a time series that crosses the change needs the correspondence table and any backcasting plan that Eurostat and its partners publish. The table shows the link. It does not remove the break.

How is a merged class checked?

The check has three parts. First, read the explanatory note for the Rev. 2.1 class, including its inclusions and exclusions. Eurostat publishes explanatory notes that give guidance for specific categories, and the notes state the content of each category. Second, read the correspondence rows that feed into the class, to see which old headings contribute activities. Third, confirm the entry for a specific business with the national statistical institute or the business register that holds the record. The institute or register holds the entry. This site holds no register and decides no entry. Where the old headings differ in scope, the note for the new class, not the old titles, governs how the combined heading is read.

Where does the count of classes fit?

The adopted structure has 22 sections, 87 divisions, 287 groups and 651 classes (FIXED, as adopted), with 36 more classes than in NACE Rev. 2. The net increase does not mean that merges were rare or common. Merges reduce the count, splits and new classes raise it, and renames leave it unchanged. The count is therefore a poor guide to how much rearrangement happened. The correspondence tables are the detailed record. Eurostat states that classes for which some activities move from a Rev. 2 class to another Rev. 2.1 class are presented in the correspondence tables. Classes with no movement need no row, and their absence from the tables is itself information: nothing in the table moves those activities.

A merged heading is best read as a question about scope, answered first by the explanatory note for the new class and then by the institute or register that holds the entry.