An international sale agreement establishes the terms for a transaction between a seller and buyer located in different countries. LegalZoom's sample agreement template includes information placeholders that are easy to fill out and complete.How do I write a Sales Agreement? Specify your location. Purchase and Sale Agreement. A purchase and sale agreement is a contract between a buyer and seller for transacting a property in exchange for a specific price. Before entering into the contract, both parties involved should negotiate the sales and service commitments outlined in the agreement. Before filling in the details of your real estate purchase agreement, identify the state where you will execute the contract. Create, commit to, and manage your agreements all in one platform with Docusign IAM. Electronically sign for free.