In this case the promissory contract also applies to third parties and prevents a bona fide purchase. The registration is valid for six months and can be extended for another six months. The Parties. The parties of a real estate sale contract are the vendor (vendedor) and the vendee (comprador). In Portugal only an unmarried or divorced vendor can sign the preliminary contract by himself. Simply stated, a promissory note is a written promise to pay. These documents contain the terms of the agreement, including the lender, the borrower, how much is being borrowed, and the frequency and amount of payments. Promissory Note for Car Sample Name and Address of Borrower Name and Address of Lender Principal Amount of Car Loan This Note is to document the sale of Make of Car, VIN number, model, year of manufacture owned by the Lender, who has the legal right to sell the car to the Borrower.