There are approximately 1 000 national experts seconded to the European Commission from the 27 EU Member States, the EFTA States and other countries. The aim of the arrangement is to supply the Commission with expertise that is not available internally and to be a tool for the European Union to increase and spread knowledge of the European institutions and decision-making process. For the employers seconding experts, the arrangement is an opportunity for international training and hands-on experience in policy areas of the EU that are important to their staff. The experts remain employees of their national employers throughout the secondment period and can stay at the Commission between six months and four years.

The obligations of all EEA EFTA national experts towards the EU institutions in which they are seconded are identical. From an administrative and legal point of view, however, the EEA EFTA national experts fall into two categories depending on their connection to the EEA Agreement:

1. EFTA in-kind experts are directly linked to the EEA Agreement as they are part of the EEA EFTA States’ annual contribution to the administrative costs of the EU budget, within the framework of EEA EFTA participation in various EU programmes, agencies and undertakings. All administrative procedures linked to their recruitment, prolongation and replacement are handled by the EFTA Secretariat in Brussels, with the exception of the experts seconded to Eurostat in Luxembourg.
2. Bilateral experts are seconded by each EFTA State to the EU outside the EEA EFTA budget. All administrative procedures linked to their recruitment, prolongation and replacement are handled by the EFTA States' respective missions in Brussels.

1. EEA EFTA in-kind experts

National experts seconded to the European Commission within the framework of the EEA Agreement and EEA EFTA participation in EU programmes and agencies.

2. EEA EFTA/EFTA bilateral experts

National experts seconded to the European Commission on a bilateral basis

National experts seconded to other European institutions and agencies on a bilateral basis