The proof of sale for a vehicle from a dealer is the Retail Certificate of Sale (MV-50) ("Dealer's Bill of Sale"). Instructions. The new owner's social security number, taxpayer identification number (TIN), or federal employer identification number (EIN) is required.You are free to draft your bill of sale in any language but you will need to translate it into English if you intend to use it as evidence in a legal dispute. Explore the ins and outs of Bills of Sale in our comprehensive guide, ensuring confident and secure buying and selling transactions. Translation for 'bill of sale' in the free English-Spanish dictionary and many other Spanish translations. Language and Copy Requirements. Language: You can draft your bill of sale in any language if you fill it with an accurate English translation. Spanish Bill of Sale forms covering transactions such as the sale of a car, electronics, jewlery and more. A motor vehicle bill of sale is between a buyer and a seller of a car, truck, or motorcycle. It is signed as the last step in the sales process.