An exchange agreement is a written agreement between the exchanger and the Qualified Intermediary (QI) defining the transfer of the relinquished property. An exchange contract is an agreement between two parties that governs the terms of an exchange of goods, services, or money between them.Once the buyer's and seller's solicitors are ready to exchange contracts, they will each seek authority to carry out the exchange from their respective clients. The exchange means that the buyer and seller have signed a contract that accepts the sale of the property. Have the following meaning when used in the Agreement: 2.1.