A part exchange or part exchange deal is a type of contract. In a part exchange, instead of one party to the contract paying money and the other party supplying goods/services, both parties supply goods/services, the first party supplying part money and part goods/services.Whether a part exchange is a sale or a barter is a fine point of law. It depends from whether a monetary value is assigned to the non-money goods supplied. Several cases at law clarify this.