Member States have to provide their annual and quarterly national main aggregates data at or before the legal deadlines to Eurostat. These data are validated and without further processing published in the Eurostat database.
Member States' national annual and quarterly data are revised according to national schedules (see questionnaire on revision practices), and revisions are applied to Eurostat's online database as soon as they become available to Eurostat.
The questionnaire on QNA provides further information on how countries compile their quarterly national accounts. It includes information on the chain-linking methodology applied by Member States and the seasonally adjusted data.
Many Member States provide a description of the sources and methods they use for the compilation of the quarterly national accounts. Most Member States also described their practises regarding the estimation of employment data. These documents are available on the pages ‘QNA Inventories’ and ‘Employment questionnaires’.