Data for the Business Register are obtained from administrative sources, the most important of which is the Tax Administration. The official financial statements data of the Finnish Patent and Registration Office are also utilised in the production of data.
Statistics Finland collects some of the data directly from enterprises and corporations with inquiries examining, for example, industry, number of personnel and data related to the establishment structure. Inquiries are sent annually to the majority of multi-establishment enterprises and, based on rotation, to single-establishment enterprises with more than 20 employees. The same units are not included every year. New enterprises, approximately the 2,500 largest ones, are inquired in January of the year following the year in which they started their operation.
In addition to this, Statistics Finland uses several other sources to gain information about changes in industry, location addresses and telephone numbers, for example.