Tertius (law)
Tertius is the Latin word for "third", or "concerning the third". The term is used in contract law to refer to an interested third party not privy to a contract.
In the English Common Law system there is no recognition of the principle ius quaesitum tertio whereby a third party may enforce a promise due unto it under a contract to which it is not a party. However, in several legal systems, including U.S. and Scots contract law, this does not bar parties to a contract from specifying that a third party is to be a beneficiary of such contract.
In Scots law, the jus quaesitum tertio principle was abolished by the Contract Act 2017 and replaced with a statutory right to enforce or invoke provisions of a contract.
Rights, particularly in property, that ordinarily do accrue to a third party are termed jus tertii.
