A parental authorisation
is an official document issued to a minor travelling abroad without his/her parents.
When your minor child leaves Belgian territory, he/she takes along his/her electronic identity card (for the under-18s) or Kids ID (for the under-12s).
report to the population department office with an identity card so as to complete and sign the parental authorisation and the signature, apposed before the relevant official, has to be authenticated by the municipality.
It may be obtained by
each of the parents (possibly with the permission of the other parent) or the guardian if the latter can produce a document to show the person's entitlement.