Travel documents for minors – Netherlands
Other than their own valid travel document (passport or ID card), no particular extra official authorisation is required for minors of any EU country to enter or leave the Netherlands. However the Dutch Marechaussee (border police) can check if children travelling with a parent with a different last name are in fact related to that person. To avoid problems, it is advisable to carry a consent form.
Minors who don't have a valid passport or identity card can obtain a special document to make sure they can go on school trips etc. (only to other EU countries) without being accompanied by their parents. You can request this document from the Dutch Immigration authorities.