Negotiorum gestio ([nəˌgō.shē-ˈȯr-əm-ˈgestēˌō], Latin for "management of business") is a form of spontaneous voluntary agency in which an intervenor or intermeddler, the gestor, acts on behalf and for the benefit of a principal (dominus negotii), but without the latter's prior consent.
This form of intervention is classified as a quasi-contract and found in civil-law jurisdictions and in mixed systems (e.g. Louisiana, Scots, South African, and Philippine laws).
For example, while you are traveling abroad, a typhoon hits your home town and the roofing of your house is in danger.
In Napoleonic jurisdictions, as well as others like Louisiana, the action takes the form of the actio de in rem verso.
In South Africa, on the other hand, multiple restitutionary actions lie for negotiorum gestio, namely: Negotiorum gestio is not recognised at common law, despite certain English salvage cases, as well as some cases in equity where trustees were on occasion remunerated for services voluntarily rendered.