Third party
From Bilat-Wiki
Legal entities which participate in Horizon 2020 by carrying out some tasks in an action, but which do not sign the Grant Agreement(GA) (including entities linked to the beneficiaries) are considered as "third parties involved in an action" (Articles 1 and 8 of the General Model GA - multi-beneficiary). They are not bound by the terms and conditions of the Grant Agreement and consequently, the European Union (represented by the Commission or another funding body) has no obligation vis-à-vis third parties. If necessary to implement the action, beneficiaries may use contracts and sub-contracting for the purchase of goods, works or services, in-kind contributions provided by third parties.
No corresponding US term.