The Office is responsible for investigating offences under the Decree for the Reasonable Restriction of Underage Sorcery and the International Confederation of Wizards Statute of Secrecy. The Decree prohibits an underage wizard or witch from performing magic, while the Statute of Secrecy prohibits wizards and witches from performing magic in the presence of Muggles or in a Muggle-inhabited area.
Also, this is where the Animagus registration is posted, and that all Animagi must register with all their distinguishing features and traits noted, in order for them not to abuse their abilities. The registry is open to public viewing. Failing to register will receive a sentence in Azkaban.