Eurostat collects its data from National Statistical Institutes that each have their own traditional methodology on processing demographic data. Therefore, it is important to set down common basic standards when it comes to joining together the data coming from different countries. The Legislations below are in force in the domain:

• Regulation (EU) No 1260/2013 of the European Parliament and of the Council of 20 November 2013 on European demographic statistics. Text with EEA relevance
• Commission Implementing Regulation (EU) No 205/2014 of 4 March 2014 laying down uniformed conditions for the implementation of Regulation (EU) No 1260/2013 of the European Parliament and the Council on European demographic statistics, as regards breakdowns of data, deadlines and data revisions Text with EEA relevance
• Regulation (EC) No 223/2009 of the European Parliament and of the Council of 11 March 2009 on European statistics and repealing Regulation (EC, Euratom) No 1101/2008 of the European Parliament and of the Council on the transmission of data subject to statistical confidentiality to the Statistical Office of the European Communities, Council Regulation (EC) No 322/97 on Community Statistics, and Council Decision 89/382/EEC, Euratom establishing a Committee on the Statistical Programmes of the European Communities. Text with relevance for the EEA and for Switzerland
• European Parliament and Council Regulation (EC) No 862/2007 on Community statistics on migration and international protection and repealing Council Regulation (EEC) No 311/76 on the compilation of statistics on foreign workers
• Commission Regulation (EU) No 351/2010 implementing Regulation (EC) No 862/2007 of the European Parliament and of the Council on Community statistics on migration and international protection as regards the definitions of the categories of the groups of country of birth, groups of country of previous usual residence, groups of country of next usual residence and groups of citizenship