The condictio indebiti is an action in civil (Roman) law whereby a plaintiff may recover what he has paid the defendant by mistake; such mistaken payment is known as solutio indebiti. This action does not lie
The action is extant in civil (Roman) or hybrid law regimes, e.g. Norway,[4] South Africa and Scotland .[5]
§ 812 I 1 1. Alt BGB (German Civil Code)