What is a principal activity?

A principal activity is the activity that contributes most to the total value added of a statistical unit. Eurostat states the definition in paragraph 59 of the introductory guidelines in the NACE Rev. 2.1 manual. One code is assigned to each unit in a statistical business register according to that activity. The definition is statistical only. It does not determine a code for a specific reader, and it does not decide tax, licensing or eligibility.

How is a principal activity defined?

The manual defines the principal activity by reference to value added. Paragraph 59 states that the principal activity of a statistical unit is the activity which contributes most to the total value added of that unit. Paragraph 71 adds that the principal activity should ideally be determined with reference to the value added associated with each activity, valued as gross value added at basic prices. The same paragraph defines that concept as the difference between output at basic prices and intermediate consumption at purchasers prices.

The definition sits inside a hierarchy. A unit is classified to a single class for its principal activity, and that class sits inside one group, one division and one section. The Eurostat glossary states that classification is carried out in stages from the section, which is one letter, down to the class, which is four digits, through the division and the group. The classification at each level must be compatible with the previous level. A principal activity label therefore always carries its full chain of levels with it, even when only the four digit class is quoted.

What happens when activities are diversified?

Paragraph 59 also covers the diversified case. Activities of a unit can be so diversified that no single class accounts for the majority of total value added. In those instances, the principal activity is identified according to the top down method, described in paragraphs 87 to 89 of the manual. The top down method is covered in a separate guide in this cluster. The point here is narrower: diversification does not remove the need for one principal activity. It changes the rule used to identify it, from a direct majority to a staged comparison down the hierarchy.

Paragraph 68 states the same requirement from the register side. A unit may perform one or more activities classified in one or more classes. For each unit, the principal activity is classified, and identification of a principal activity is necessary to allocate a unit to a single class. All activities are considered when the principal activity is determined, but only the principal activity is used to classify a unit. Secondary activities are recorded as activities of the unit, but they do not supply the classifying code.

How does the definition appear in a record?

| Item | What the manual states |

|---|---|

| Unit | A statistical unit, such as an enterprise or a kind of activity unit |

| Principal activity | The activity contributing most to total value added |

| Register code | One code per unit, assigned by principal activity |

| Hierarchy | Section, division, group, class, each level compatible with the level above |

The table states the record in the terms the manual uses. It does not show a code for any real unit, and no row in it can be read as a determination. The register code row records the rule in paragraph 69: one code is assigned to each unit recorded in statistical business registers according to its principal economic activity. The same paragraph adds that a code is also assigned to units that enter the register without any obvious economic activity, associated value added or substitutes, with a reference to groups 64.2 and 64.3. That special case is a register rule, not a general shortcut, and the manual points the reader to the explanatory notes for those groups.

What does this classification not decide?

A classification entry describes an activity for statistical purposes. The introductory guidelines state the limit in their own terms: for a specific unit, the entry decides no question of tax, social security, a collective agreement, licensing or funding eligibility. The authority or register deciding those questions, under the law governing each question, is where they belong. A reader who treats a statistical entry as a decision about eligibility is reading more into the entry than the classification states. In the guardrail box the same limit appears, and confirmation of a specific unit entry rests with the institute or register holding the record.

Where is the entry confirmed?

The checking sequence for this subject is short. First, the introductory guidelines for the rule as Eurostat published it. Second, the explanatory note for the category, for what the category includes and excludes. Third, the institute or register, for the entry actually held. No other source in this guide replaces any step in that sequence.

Read the definition in paragraph 59, follow the hierarchy down to the class, and confirm the entry held for a unit with the institute or register that holds it.