It is in the interest of the foreign national, the authority of the country of origin and the Immigration Office that the identification procedure is rapid. To avoid unnecessarily long detentions, the Immigration Office has decided to try to determine the identity and nationality of third-country nationals who are irregularly staying before they are sent to a detention centre for their return. The advantage is that the identification process can start before the end of the detention. In that case, applying for the travel document at the relevant diplomatic or consular representations is only necessary.

Foreign nationals incarcerated for common law offences are placed at the disposal of the Immigration Office after they have served their sentence. The Immigration Office then makes a decision based on the residence situation of the person concerned and the potential danger they represent to society. Since 2005, the Immigration Office has had an operational service exclusively responsible for identifying of foreign nationals detained in prison. Return coaches have been appointed for this purpose. They must persuade the irregularly staying foreign nationals to provide information about their identity and nationality.

It is the individual's best interest to cooperate, as this may influence the decision of the sentencing court, which could grant early release based on various elements, including willingness to cooperate with identification and return. The return coaches also act as intermediaries between the foreign nationals in prison and the Immigration Office. During an interview, the return coach must explain their administrative situation to the detainee. Therefore, to organise a quick and efficient repatriation from prison and avoid the transfer of a former detainee to a detention centre, this person must be identified before release. It is in the foreign national's interest so that their administrative detention is not prolonged unnecessarily after serving their sentence.