Prior to accession to the European Union, each would-be Member State needs to ensure that all basic EU legislation is translated into the language that it would like to become a new EU official language. This concerns firstly primary legislation, namely the Treaties, but also a raft of secondary legislation, i.e. directives, regulations and decisions as well as agreements, Court judgements, etc.

The TAIEX instrument provides the main assistance to the candidate countries in their significant efforts to achieve this task within the time frame leading up to accession. TAIEX involvement has included support for the establishment of Translation Coordination Units (TCUs) in the countries themselves, and the continued co-ordination over the following . The CCVista database, created as a repository for translations, continues to play a key role as an interface for the finalisation process managed by the EU Institutions through its lawyer-linguists.