Minors applying for a Belgium visa must provide the following additional documents:
If the minor is travelling with only one parent, written consent certified by a public notary of the other parent or guardian, except in cases of a parent having sole custody or guardianship of the minor, in which case a court order or other proof of sole custody or guardianship must be provided;
If the minor travels alone (without parents), written consent, certified by a public notary, of both parents or guardians having custody or guardianship of the minor;
Copy of identification document(s) (with signature and photograph) of the parent(s)/guardians having custody/guardianship of the applicant.