The law provides for a maximum of a 2-month detention period for asylum seekers. Detention can be prolonged for another 2 months for reasons of national security or public order. Where extended for these reasons, a one-month prolongation if possible each time. The maximum duration of detention on territory therefore cannot exceed 6 months (2+2+1+1). The detention at the border may not exceed 5 months. However, the period of detention is suspended for the time provided to appeal the decision on the asylum application.
However, when an asylum seeker refuses to board a plane, the detention period can sometimes be longer than 6 or 5 months. In this situation, a practice is applied by the Immigration Office in which the detention period is reset to zero. Although such a practice received criticism as to creating a situation of indefinite detention duration, it was confirmed by the Belgian Court of Cassation. The case was afterwards brought before the ECtHR in the Kabongo v. Belgium case. In that case, Miss Kabongo, a national of the Democratic Republic of Congo refused to board planes to Southern Africa five times. The Immigration Office took a new decision of detention for a period of 5 months, as a result of which Miss Kabongo was detained more than 10 months. The ECtHR ruled that, considering the multiple attempts by the Immigration Office to remove Miss Kabongo from the territory and her systematic opposition to this, the practice could not be seen as a violation of Article 5 ECHR.
Asylum seekers in the Dublin procedure may be detained to determine the responsible Member State and secure a transfer. In both cases detention may not exceed 6 weeks.
On 19 July 2019, Article 51/5/1 of the Aliens Act entered into force and implements the relevant articles on detention of the Dublin III Regulation for applicants who did not apply for asylum in Belgium, but who could be subject to a take-back decision because of a previous application that was registered in another Member State.
Contrary to the Dublin III Regulation, the law does not mention that the detention should be as short as possible. Furthermore, when a transfer decision is being appealed through an extremely urgent necessity procedure, the detention period starts again. This means that a new period of six weeks will start after the rejection of the appeal in the extremely urgent necessity procedure.
When detained at the border, asylum seekers generally spent more time in detention than other migrants in detention. Asylum seekers are admitted to the territory if the CGRS has not taken a decision within four weeks, or when the CGRS decides that further investigation is necessary. However, being admitted to the territory does not automatically mean that the asylum seeker will be set free. As shown in practice, the Immigration Office takes a new detention decision based on one of the grounds set out in Article 74/6(1) of the Aliens Act, which regulates detention on the territory.
While the duration of detention of asylum seekers is unknown in practice, the Immigration Office stated that the average duration of detention of all persons detained in immigration detention was 27.9 days in 2021.
 Articles 74/5 and 74/6 Aliens Act.
 Gesloten centra voor vreemdelingen in België: een stand van zaken, December 2016, available in Dutch at: https://bit.ly/3DH0nZS.
 Belgian Court of Cassation, Application No° A.R. P.04.0363.F, nr. 173, Judgment of 31 March 2004.
 ECtHR, Nancy Ntumba Kabongo v. Belgium, Application No. 52467/99, Judgment of 22 June 2005, p 18-20.
 Before this legal amendment, the minister could not delegate these decisions to a staff member of the Immigration Office.
 Article 74/5(4)(4) and (5) Aliens Act, as amended by the Law of 21 November 2017.
 See more explanation on this practice in Nansen, Vulnerability in detention: border procedures, fast-track procedure and videoconference (2019-2020), available in French at: https://bit.ly/3lc5tqA.
 Information provided by the Immigration Office, February 2022. In 2017, this was 34,6 days; see: Myria, ‘Myriadoc 8: Retour, détention et éloignement’, December 2018, available in French at: https://bit.ly/2FPAo6t, 10.