a natural person assigned to the project on the basis of a contract against payment with a beneficiary institution.

Интересует именно перевод a contract against payment

Знающие, подскажите, пожалуйста.

банк получателя
банк бенефициар
банк бенефициара

In the context of a Capacity Building in Higher Education (CBHE) project staff can be either:
a) employed by a beneficiary institution and therefore part of its payroll system;
b) a natural person assigned to the project on the basis of a contract against payment with a beneficiary institution.

In the case of a "natural person", the individual concerned can be assigned to the project on the basis of e.g. a civil contract, a free-lance contract, an expert contract, a service contract with self-employed person ("in house consultant") or a secondment to a beneficiary institution against payment.

тогда так все и получается общо - на договорной основе за деньги,
и именно с ним могут быть заключены: договор типа А, договор типа Б и т.д...