First, all the candidates must state in their application the languages in which they would be prepared to take the tests (notably for the assessment centre tests), in the knowledge that the minimum level required is B2.
At the end of this first registration phase, EPSO will compile all the data from all the applications to extract the languages most frequently declared by the candidates. The five languages most frequently declared by the applicants will be proposed to the Institutions. If they approve these languages, they will be offered to the candidates for their tests at the assessment centre.
Second, the candidates must complete and validate their application by choosing from these five languages the one in which they will ultimately take the assessment centre tests. This is also the same language in which the candidates must fill in their entire application form. At this stage the candidates must also choose the language in which they will take most of their multiple-choice questions (MCQ) tests. (This can be any official EU language, but must be different from the second language.)