How does the section letter shift work in Italy?

ATECO 2025 follows the same section letter shift as NACE Rev. 2.1: the old Section J became Section J and Section K, with the sections that followed moving one letter forward. ATECO 2025 is consistent with NACE Rev. 2.1, as Istat states, and the European structure is shared at the levels the two classifications have in common. In the new structure, publishing, broadcasting and content production and distribution activities sit in Section J. Covered by Section K: telecommunication, computer programming, consulting, computing infrastructure and other information service activities.

An Italian heading that sat after the old Section J therefore carries a new letter under ATECO 2025, even where its activities and lower level numbers are unchanged. For a pure renumbering, the letter changed while the content did not.

How does the shift show in the Italian structure?

The shift shows in the section list. The EUR-Lex summary lists 22 sections for NACE Rev. 2.1, in order, with the two new sections at J and K, and with financial and insurance activities at L, real estate at M, and the remaining sections following in order. The Italian structure follows the same order at the shared levels, with Italian titles published by Istat in Italian, English and German. A reader who compares an ATECO 2007 code with an ATECO 2025 code should therefore check the section letter against the version, not alone. A letter that meant one section under the old version can mean the next section under the new version. The shift is mechanical, but its effect on datasets is large, because every section from the old K onwards is affected, and a dataset that stores letters without versions will misplace all of them.

Position	Old structure	New structure
At the split	A single section for information and communication	Section J content, plus Section K telecommunication and information services
After the split	Each later section one letter earlier	Each later section one letter later
Section count	Fewer sections, before the split	22 sections, as listed in the EUR-Lex summary

The table above describes the mechanism in general terms. It does not list Italian section titles beyond the two new sections, because Italian titles must be read in the Istat structure, and this guide does not assert them from a secondary summary.

How is a shifted heading distinguished from a restructured heading?

Together, the correspondence row and the explanatory note show whether a heading was shifted or restructured. A pure shift shows a one to one row, unchanged division, group and class numbers, and a new heading note matching the old heading note. A restructure coinciding with the shift appears as movement in the row, added or removed content in the note, or both. Because the letter changes in both cases, the letter alone cannot make the distinction. A reader must therefore check the row in the Istat bidirectional correspondence table, and the note for the new heading, before concluding that a new letter means only a new address. The check is heading by heading. The position for a particular heading is not proved by a general statement about the shift.

What errors does the shift cause in Italian datasets?

The shift causes two errors in Italian datasets. The first is misplacement: a figure filed under the old letter for a later section is read as if it belonged to the section that now carries that letter. The second error, false continuity, joins a figure filed under the new letter to an old figure filed under the same letter, even though the sections described differ. Storing the letter without the version gives rise to both errors. The remedy has three parts: the version stored beside every code, the version stated in every publication note, and series joined through the correspondence tables and any backcast series, not by letter. Istat publishes the structure in three languages, which helps readers who work across languages, but a translation does not remove the version risk. The version must be stated in every language version used.

What the shift does not decide

Neither the code for any reader nor any tax, licensing, funding or collective agreement question is decided by the shift. Within the classification, it is a change of addressing. For a specific business, Istat or the business register that holds the record is where the entry is confirmed. This site holds no register and decides no entry. No new obligation comes from a new letter, and no old obligation is preserved by an unchanged number. Authorities applying their own rules are where those questions belong.

Sections after the old Section J moved one letter forward in ATECO 2025, a new letter proves only a new address, and the Istat row and note for each heading show whether its content moved as well. ”