unjust enrichment; excessive profit
Legal and formal term for receiving a benefit without a valid legal basis, often used in civil law contexts.
不当利得の返還を求める訴訟を起こした。
They filed a lawsuit seeking restitution of unjust enrichment.
契約が無効になった場合、不当利得として支払った金を返してもらえることがある。
If the contract becomes void, you may be able to get back the money you paid as unjust enrichment.