01. sale of goods principles

The question

The sale of goods is the paradigm commercial transaction, the exchange of goods for a price that lies at the foundation of trade. The general law of contract examined in the previous module governs the sale of goods as it governs every contract, yet the sale of goods raises particular questions that the general law does not answer and that a specialised body of rules has developed to address: when ownership of the goods passes from seller to buyer, who bears the risk of their loss, what quality the buyer is entitled to, and what happens when a seller sells goods it does not own. This sub-unit examines those questions at the level of principle, before the next sub-unit turns to the specific convention that governs international sales. The answer introduces a set of concepts, common across the traditions, that govern the transfer of goods and the allocation of their risks.

The contract of sale and the obligations of the parties

A contract of sale of goods is a contract by which the seller transfers, or agrees to transfer, the ownership of goods to the buyer in exchange for a money price. The definition identifies the two defining features of the transaction: the subject matter is goods, meaning movable tangible things, as distinct from land or from intangible rights, and the consideration is a money price, as distinct from other goods, which would make the transaction an exchange rather than a sale. The contract of sale is the specialised commercial application of the general contract examined in the previous module.

The contract imposes correlative obligations, broadly common across the traditions, that connect to the analysis of obligation in Course 1. The seller's principal obligations are to deliver the goods, to transfer ownership of them, and to ensure that they conform to the contract in quantity, quality, and description. The buyer's principal obligations are to take delivery of the goods and to pay the price. These obligations are the content of the sale, and a failure to perform any of them is a breach governed by the principles of the previous module, the seriousness of the breach determining whether the innocent party may terminate or is confined to damages.

Consider a contract for the sale of a quantity of manufactured components. The seller must deliver the components, transfer ownership of them to the buyer, and ensure they conform to the contract in number, quality, and specification; the buyer must accept delivery and pay the agreed price. Each obligation is owed by one party to the other, and the breach of any gives rise to the remedies the law of contract provides. The example shows the contract of sale as a structured set of correlative obligations specialising the general law of contract for the exchange of goods.

The contract of sale of goods is therefore the transfer of ownership of movable things for a money price, imposing on the seller the obligations to deliver, to transfer ownership, and to supply conforming goods, and on the buyer the obligations to take delivery and to pay, the whole governed by the general law of contract as specialised for the sale.

The passing of property and the passing of risk

Two questions of timing are central to the sale of goods, and they must be kept distinct because they answer different problems and need not coincide. The first is the passing of property, also called the passing of title, the moment at which ownership of the goods transfers from seller to buyer. The second is the passing of risk, the moment at which the danger of accidental loss of or damage to the goods transfers from seller to buyer, so that the party who bears the risk suffers the loss if the goods are destroyed or damaged without either party's fault.

These concepts connect directly to the distinction between real and personal rights examined in Course 1. The passing of property determines who owns the goods, and hence who has the real right that avails against the world, a matter of the first importance if either party becomes insolvent, since the owner may claim the goods ahead of the other's general creditors. The passing of risk determines who bears the loss if the goods perish, and hence who must still pay or deliver despite the loss. The two need not pass together: the rules of the governing system, or the parties' own agreement, may provide that risk passes on delivery while property passes at a different moment, and in international sales the Incoterms examined later in this course are the principal means by which commercial parties fix the passing of risk precisely. Across the traditions, the parties are generally free to determine when property and risk pass, and the law supplies default rules where they have not.

Suppose goods are sold and, after the contract but before delivery, are destroyed by an accidental fire without fault. Whether the buyer must nonetheless pay the price depends on whether risk had passed to the buyer at the time of the fire: if it had, the buyer bears the loss and must pay; if it had not, the seller bears the loss. Whether the buyer, or the seller's creditors, may claim the remains or the proceeds depends on whether property had passed. The example shows the passing of property and the passing of risk answering distinct questions, the one of ownership and the other of who bears accidental loss.

The passing of property and the passing of risk are therefore the two central questions of timing in the sale of goods, the one fixing ownership and the real right it carries, the other fixing who bears accidental loss, distinct questions that the parties may allocate separately and that the law fills with default rules where they do not.

The conformity of the goods

The buyer contracts not merely for goods but for goods of a particular description and quality, and the law protects this expectation through the requirement of conformity, the principle that the goods delivered must correspond to the goods the contract required, in quantity, in quality, and in description. The requirement of conformity is the sale-of-goods expression of the seller's obligation to perform the contract, and it is supplied in part by the express terms of the contract and in part by terms the law implies.

This requirement connects to the analysis of implied terms in the previous module, for the law of sale implies into the contract, in the absence of contrary agreement, obligations as to the quality of the goods: that they will be of satisfactory or merchantable quality, that they will be fit for any particular purpose the buyer has made known, and that they will correspond to their description and to any sample. Where the goods delivered fail to conform, in quantity, quality, or description, the seller is in breach, and the buyer's remedies follow the principles of the previous module: the buyer may reject the goods and terminate if the non-conformity is sufficiently serious, or must accept the goods and claim damages if it is not. The requirement of conformity thus gives the buyer a protected expectation as to what it will receive, enforced through the ordinary law of breach and remedies.

Consider a buyer who orders goods of a stated specification for a purpose made known to the seller, and who receives goods that fail to meet the specification and are unfit for the purpose. The goods do not conform, the seller is in breach of the express term as to specification and of the implied term as to fitness for purpose, and the buyer may reject and terminate if the non-conformity is serious, or claim damages if it is not. The example shows the requirement of conformity protecting the buyer's expectation as to the goods and connecting the sale to the general law of breach.

The requirement of conformity is therefore the principle that the goods must match the contract in quantity, quality, and description, supplied by express terms and by terms the law implies as to quality and fitness, and enforced through the ordinary remedies for breach, so that the buyer is protected in its expectation of receiving the goods bargained for.

The transfer of title and the protection of third parties

A particular problem arises where a seller purports to sell goods that it does not own or has no right to sell, and the law's resolution of it balances two competing interests. The governing principle, expressed in the maxim nemo dat quod non habet, meaning that no one can give what they do not have, is that a seller cannot transfer to the buyer a better title to the goods than the seller itself holds, so that a buyer from a person who is not the owner ordinarily acquires no ownership and the true owner may recover the goods.

This principle connects to the analysis of real rights in Course 1, for ownership is a real right that avails against the world, and it would be defeated if a non-owner could transfer good title to the owner's goods. The principle protects the true owner, but it threatens the security of commercial transactions, since a buyer cannot always verify the seller's title, and the law accordingly admits exceptions, broadly recognised across the traditions, that protect a good-faith buyer in defined circumstances, particularly where the true owner has clothed the seller with the appearance of ownership or authority to sell, or where the goods are bought in good faith in the ordinary course of a market or from a seller left in possession. The law thus accommodates the competing interests of the true owner, who should not lose property to a thief's sale, and the good-faith buyer, who should be able to rely on the appearance of a regular commercial transaction, the balance struck differing in detail among the systems.

Imagine goods entrusted by their owner to a dealer who, without authority, sells them to a buyer who takes them in good faith and without notice of the want of authority. Whether the buyer acquires good title depends on whether the case falls within an exception to the nemo dat principle, such as one protecting a buyer in good faith from a seller whom the owner has placed in possession with the apparent authority to sell. Outside such an exception, the buyer acquires no title and the owner may recover the goods. The example shows the nemo dat principle protecting the owner while its exceptions protect the security of good-faith commercial dealing.

The transfer of title is therefore governed by the principle that a seller cannot pass a better title than it holds, protecting the true owner, qualified by exceptions that protect a good-faith buyer where the owner has created the appearance of a right to sell, the law balancing the security of ownership against the security of commercial transactions.