The nature and quantity of goods needed by a buyer is normally specified in a purchase contract. A seller is bound to deliver the good requested, to the buyer on an agreed consideration. Goods are called non conforming goods when the delivered goods are not the goods specified in the purchase contract.
Under the Uniform Commercial Code (UCC), if a vendor delivers non conforming goods, the buyer can reject all of the goods, accept all of the goods, or accept some and reject rest of the goods. Rejection of non conforming goods should be made by a buyer in a reasonable time after the goods are delivered. If the goods are non conforming and the buyer has rejected the goods, the buyer has no liability to pay for the goods.