Guardians ... represent the legal rights of their underage wards in their entirety (parental care).
Custodians … represent the legal rights of their underage wards to some extent (decisions on accommodation, healthcare, assets, etc.).
Guardians and custodians may be: private individuals (“sole” guardians/custodians), experts working for independent organisations (“by association”) or representatives of the youth welfare office (“official”).
Facts and figures:
In Germany, at the end of 2019
In 2019, the family courts withdrew parental custody either fully or partially in approx. 16,500 cases. The youth welfare offices are consulted in these decisions.
No child or adolescent should be without legal representation. Normally, they are represented by parents with joint custody or a single parent with sole custody. Custody may be transferred from birth parents to guardians (fully) or custodians (partially) by order of the family court, with involvement of the youth welfare office. This is done when parents are unwilling or unable to exercise their custody rights themselves, or when the manner in which they do so fails to avert danger to their child(ren)’s welfare or may even cause endangerment (abuse, neglect, sexual violence).
The Civil Code (BGB) recognises various forms of guardianship: the official guardianship of the youth welfare office by appointment (Section 1791b), official custodianships (Section 1909) and two types of statutory official guardianship (Sections 1791c, 1751). An official guardianship is imposed by law when a child is born to an underage mother who is not married to the child’s father, or when parents give up their child for adoption.
Once custody rights have been transferred to another person or a guardian, they have the right and the duty to care for their underage ward (Section 1800), e.g., to determine where they are to live, to apply for assistance and, if rejected, lodge an appeal. They carry sole responsibility for ensuring their ward’s welfare and as a rule are independent in doing so. Furthermore, since 2011 guardians and custodians have been required by law to maintain personal contact with their wards, usually once monthly (Section 1793 [1a]).
There are “sole” guardianships and custodianships, guardianships and custodianships “by association” and “official” guardianships and custodianships. In the latter case, once withdrawn from the parents the custody rights are transferred to the youth welfare office (Sections 1791a, 1791b), which delegates the task of guardian or custodian to one of its representatives. They act as the legal representative of the child or adolescent in accordance with the extent to which the rights have been transferred to them (Article 55  of Book 8 of the Social Code [SGB VIII]).
Besides the partial or full withdrawal of parental custody rights by the family court, Section 1666 of the Civil Code allows the family court to impose instructions or prohibitions, for instance instructions to seek public assistance or ensure that the child attends school, or prohibitions on contacting the child or using a certain kind of accommodation (cf. Münder 2017).