What must I do to authorise that my child can travel with a relative or guardian?
Any child going abroad without a parent or legal guardian must have a letter of consent, otherwise permission to travel may be refused. The child must also have a passport in their own name, travel will not be permitted where a child is included on a parent/guardian passport and the parent/guardian is not present.
If you intend on taking a French child, under the age of 18, to the UK, please be aware that, in addition to a letter of consent and identity card, you will also need a 'Sortie de Territoire', if you are not the child's parent or guardian.
Once completed and signed by the parent or guardian, the 'Sortie de Territoire' must be presented with either the child's passport or National Identity Card, along with a photocopy of the respective parent or guardian's valid passport or identity card. If this is not obtained, permission to travel is likely to be refused. Download the authorisation letter here (only available in French).