Sales indices in retail trade and personal services make it possible to measure the monthly developments in the volumes of sales in the sectors concerned. Turnover indices in value in the same sectors are also available.

Sales indices and turnover indices in retail trade and personal services focus on a national and European need. They relate to the European regulations on short-term statistics ("STS" EC regulation n° 1165/98 of the Council of 19 May 1998, updated by subsequent amendments).

In order to reduce the statistical burden on businesses and because the data has been collected on a regular basis, Insee obtained the ability to use businesses' value-added tax (VAT) declarations in order to calculate a set of monthly indices showing the developments of turnover.

The Tax General Directorate transmits to the Insee the declarations of VAT. Until 2015, the index of turnover were calculated from a sample of companies declaring the VAT monthly, selected by INSEE.

This sample of almost 160 000 companies was renewed on an annual basis. It includes an exhaustive section (the largest businesses in each sector) and is selected in proportion of the turnover over the rest of the field.

From 2016, all the monthly declarations are exploited for the calculation of the indices.