Who publishes ISIC and why is it global?

ISIC Rev. 5 is maintained by the UN Statistics Division, which sits inside the United Nations system and works with national statistical offices around the world. That UN custodianship is what makes the classification global: countries can adapt it for national use while keeping a common reference point for international comparison. No single company, trade body or national office owns the international standard itself.

What does UN custodianship actually consist of?

Custodianship here means maintenance, not ownership in the commercial sense. ISIC Rev. 5 is maintained by the UN Statistics Division, which sits inside the United Nations system and works with national statistical offices around the world. The Division keeps the structure, publishes its definitions and notes, and provides the common reference point against which national adaptations can be checked. No single company, trade body or national office owns the international standard itself, and that absence of a private owner is part of why the standard can serve as a shared reference. A standard owned by one country’s office, or by one industry body, would always carry the suspicion that it served its owner first. A UN custodian, working with national offices collectively, is positioned to serve comparability itself.

That positioning also shapes how the standard changes. Because national offices use the structure in their own surveys and registers, a revision cannot be a unilateral announcement. It must be a process those offices can follow, plan for and phase in, with documentation that lets each of them map old categories to new ones and explain breaks in their own series. The global character of ISIC is therefore not a slogan attached to the title. It is a working relationship between a custodian and the offices that actually collect the data.

How does a shared reference travel from questionnaire to chart?

Inside a national statistical office, the shared reference does its work through a chain. The survey questionnaire asks about activity in words. The coding manual turns those words into categories. The published table presents the results under category titles. All three stages must point to the same category definitions, or results will drift between collection and publication in ways no reader of the final table can detect. ISIC Rev. 5, UN Statistics Division, provides that reference, so the coder, the analyst and the reader work from the same structure rather than from three local approximations.

How should a reader walk the hierarchy under a global standard?

The walk is the same in every country that uses the standard, and that sameness is the point. Start from the activity described in words, then move through the hierarchy from broad to fine, checking each level against the UNSD structure for ISIC Rev. 5, UN Statistics Division. At every level of ISIC publishing, test whether the definition still fits, whether an excludes list redirects the activity, and whether a finer level adds meaningful detail. If ISIC publishing leaves the answer unclear at any level, remain at the broader level that is clearly correct and record the question, rather than choosing a fine category that cannot be justified from the evidence available. A reader in any country following that walk on the same structure should reach the same grouping, and that reproducibility is what makes international comparison more than a hopeful metaphor.

Why does a change in ISIC ripple so widely?

ISIC does not stand alone. It connects to national accounts, to business registers, to product classifications and to the classifications used for occupations and trade, and its value grows when those connections are kept clean. A change in ISIC therefore ripples into the tables that use it, which is why revisions are planned, documented and phased in, rather than introduced silently. A reader who sees that wider system will understand why a classification change is treated as a serious statistical event, not a renaming exercise. Keep these points in view:

• Word the activity first, instead of starting from a code remembered from a previous revision.
• Read the explanatory note for a category before settling, particularly where two titles look alike.
• Carry the version label, ISIC Rev. 5, UN Statistics Division, with every code you pass on.
• If detail cannot be supported, report at the broader level that is clearly right.
• Record any break in series when figures from different revisions appear together.

The safest next step, whenever a category looks uncertain, remains a modest one: open the UNSD Rev. 5 structure, read the note for the category in question, and note the version beside any number you carry forward. That small discipline is where global comparability actually happens, desk by desk.

This guide is about the custodianship and global use of a statistical classification. It makes no decision about any reader’s code, principal activity or registration, and the place to confirm a code for a particular record is the national statistical institute or business register holding that record.