A
third-party beneficiary, in the
law of
contracts, is a person who may have the right to sue on a contract, despite not having originally been an active
party to the contract. This right, known as a
ius quaesitum tertio, arises where the third party (
tertius or
alteri) is the intended beneficiary of the contract, as opposed to a mere incidental beneficiary (
penitus extraneus). It
vests when the third party relies on or assents to the relationship, and gives the third party the right to sue either the promisor (
promittens, or performing party) or the promisee (
stipulans, or anchor party) of the contract, depending on the circumstances under which the relationship was created.