Merchant law is the set of rules that governs commercial sales of goods when at least one party is in the business of selling them. In the United States, it lives primarily in Article 2 of the Uniform Commercial Code, a model statute adopted in some form by every state. For cross-border deals, the United Nations Convention on Contracts for the International Sale of Goods covers transactions between businesses in its 97 signatory countries. These rules fill gaps the parties did not address, impose automatic duties on professional sellers, and set the ground rules for warranties, delivery, risk of loss, and remedies when something goes wrong.
Who Counts as a Merchant
The label is the gatekeeper for everything that follows. Under the UCC, a merchant is someone who regularly deals in goods of the kind being sold, or who holds themselves out as having specialized knowledge about those goods or the practices involved in the transaction.1Cornell Law Institute. Uniform Commercial Code 2-104 – Definitions: “Merchant”; “Between Merchants”; “Financing Agency” A farmer selling a tractor at a yard sale probably is not a merchant. A dealership selling that same tractor almost certainly is.
The classification carries real weight. A merchant owes a heightened duty of good faith that includes following reasonable commercial standards of fair dealing in the trade. A casual seller only needs to be honest; a merchant has to behave the way a competent professional in the industry would. That higher standard runs through Article 2 and reshapes offers, acceptances, writing requirements, and warranty obligations.
Rules That Apply Only Between Merchants
Firm Offers Stay Open
Ordinarily, someone who makes an offer can revoke it any time before acceptance. Merchants cannot. When a merchant makes a signed, written offer that promises to stay open, the offer is irrevocable for the time stated or, if no time is stated, for a reasonable period. The outer limit is three months even if the offer promises longer.2Cornell Law Institute. Uniform Commercial Code 2-205 – Firm Offers No payment or separate consideration is needed to hold it open.
The Battle of the Forms
Real deals rarely close on a single clean document. A buyer sends a purchase order, the seller sends an acknowledgment, and the two forms do not match. The UCC lets a definite expression of acceptance form a contract even when it adds or changes terms.3Cornell Law Institute. Uniform Commercial Code 2-207 – Additional Terms in Acceptance or Confirmation Between merchants, the added terms become part of the contract unless the original offer expressly limits acceptance to its own terms, the new terms materially alter the deal, or the other party objects within a reasonable time. This replaces the old mirror image rule, which required an acceptance to match an offer word for word.
Written Confirmations and the Statute of Frauds
A contract for the sale of goods priced at $500 or more is not enforceable unless there is a signed writing that indicates a contract was made and specifies the quantity.4Legal Information Institute. Uniform Commercial Code 2-201 – Formal Requirements; Statute of Frauds The document does not need to recite every term, but the contract cannot be enforced beyond the quantity shown.
Merchants face a trap here. If one merchant sends the other a written confirmation of an oral deal, and the recipient knows what it says and does not send a written objection within ten days, that confirmation satisfies the writing requirement against both sides.4Legal Information Institute. Uniform Commercial Code 2-201 – Formal Requirements; Statute of Frauds Silence after a confirmation letter can bind a merchant to a deal they never signed.
Warranties That Attach Automatically
When a merchant sells goods, certain quality guarantees come with the sale whether the contract mentions them or not. These are the implied warranties, and they are one of the most litigated areas of commercial law.
The Warranty of Merchantability
Any time a merchant sells goods of the kind they regularly deal in, the law implies that the goods are merchantable. At a minimum, they must pass without objection in the trade, be fit for their ordinary purpose, run consistent in quality across units, and conform to any promises on the label.5Legal Information Institute. Uniform Commercial Code 2-314 – Implied Warranty: Merchantability; Usage of Trade A restaurant serving spoiled food breaches this warranty, because serving food for value counts as a sale under this section. The warranty applies only when the seller is a merchant for goods of that kind, so a hardware store selling off its old office furniture would not trigger it.
The Warranty of Fitness for a Particular Purpose
A separate warranty arises when a buyer relies on the seller’s expertise to pick goods for a specific need. If the seller knows the buyer’s purpose and the buyer is depending on the seller’s judgment, the law implies that the goods will actually work for that purpose. Unlike merchantability, this one can arise even when the seller is not a merchant, though in practice it usually involves professional sellers whose expertise buyers trust.
How Sellers Disclaim Warranties
Sellers can disclaim implied warranties, but the UCC makes them do it visibly. To disclaim merchantability, the disclaimer must specifically use the word “merchantability,” and any written disclaimer must be conspicuous. To disclaim fitness, the exclusion has to be in a conspicuous writing.6Legal Information Institute. Uniform Commercial Code 2-316 – Exclusion or Modification of Warranties Language like “as is” or “with all faults” can exclude all implied warranties at once, provided the phrasing makes clear to a reasonable buyer that no quality guarantees exist. Buried fine print will not do the job.
Delivery, Conformity, and Risk of Loss
The Perfect Tender Rule
If delivered goods fail in any respect to conform to the contract, the buyer has three choices: reject the entire shipment, accept the entire shipment, or accept some commercial units and reject the rest.7Legal Information Institute. Uniform Commercial Code 2-601 – Buyer’s Rights on Improper Delivery This is the perfect tender rule, and it gives buyers significant leverage. Even a minor deviation can justify rejection. Installment contracts work differently, allowing rejection only when a defect substantially impairs the value of that installment.
Who Bears the Loss in Transit
One of the most consequential questions in any goods transaction is who bears the loss if the goods are damaged or destroyed before they arrive. The UCC supplies defaults that depend on how the contract is structured. In a shipment contract, where the seller is authorized to ship but not required to deliver to a specific destination, risk passes to the buyer when the goods are handed over to the carrier. In a destination contract, risk stays with the seller until the goods arrive and are tendered at the agreed location.8Legal Information Institute. Uniform Commercial Code 2-509 – Risk of Loss in the Absence of Breach
When no carrier is involved and the seller is a merchant, risk does not pass until the buyer physically receives the goods. If the seller is not a merchant, risk passes upon tender of delivery. The merchant bears the loss longer, reflecting the expectation that professional sellers are better positioned to insure and protect inventory. Parties can override these defaults by agreement, and well-drafted contracts almost always do.
Remedies When a Deal Breaks Down
When one side fails to perform, the UCC provides a structured menu of remedies for both buyers and sellers. The goal is to put the injured party where it would have been had the contract been performed, not to punish the breaching party.
What the Seller Can Do
When a buyer wrongfully rejects goods, fails to pay, or repudiates the contract, the seller can withhold delivery of unshipped goods, stop goods in transit, resell the goods and recover the difference between the contract price and the resale price, or sue for damages based on the market price.9Legal Information Institute. Uniform Commercial Code 2-703 – Seller’s Remedies in General In some cases the seller can recover the full contract price, particularly when the goods cannot be resold at a reasonable price. The seller can also cancel the contract entirely.
What the Buyer Can Do
A buyer who rightfully rejects goods or justifiably revokes acceptance can cancel the contract and recover any payments already made. The buyer can also “cover” by purchasing substitute goods elsewhere and recovering the price difference, or sue for damages based on the gap between the contract price and the market price at the time of breach.10Legal Information Institute. Uniform Commercial Code 2-711 – Buyer’s Remedies in General; Buyer’s Security Interest in Rejected Goods A buyer holding rejected goods has a security interest in them for any payments already made and can resell them to recoup those costs.
Liquidated Damages and the Four-Year Clock
Contracts often fix damages at a predetermined amount in case of breach. The UCC enforces these liquidated damages clauses only if the amount is reasonable in light of the anticipated or actual harm, the difficulty of proving the loss, and the impracticality of obtaining another adequate remedy. A clause that fixes unreasonably large damages is void as a penalty.11Legal Information Institute. Uniform Commercial Code 2-718 – Liquidation or Limitation of Damages; Deposits
Any lawsuit for breach of a sales contract must be filed within four years after the breach occurs, regardless of when the injured party discovered it. The parties can agree to shorten this to as little as one year, but they cannot extend it beyond four.12Legal Information Institute. Uniform Commercial Code 2-725 – Statute of Limitations in Contracts for Sale For warranty claims, the clock starts when the goods are delivered, unless the warranty explicitly covers future performance, in which case it starts when the defect is or should have been discovered. Missing these deadlines is one of the most common ways merchants lose otherwise valid claims.
How Trade Custom Fills the Gaps
Written contracts leave gaps, and the UCC fills them by looking at how the parties and their industry actually behave. The code recognizes three gap-filling tools in a specific hierarchy. Course of performance looks at what the parties have done under the current contract when it calls for repeated actions. Course of dealing examines their conduct in prior transactions with each other. Usage of trade captures the standard practices of a particular industry, so widely followed that participants can reasonably be expected to observe them.13Legal Information Institute. Uniform Commercial Code 1-303 – Course of Performance, Course of Dealing, and Usage of Trade
These tools can give meaning to vague terms, fill in missing details, and even qualify what the written words appear to say. If a particular grade of lumber is standard in the construction industry, a buyer does not need the contract to spell that out. The expectation is built in. Contracts between merchants are read in context, not in isolation.
Merchant Law Across Borders
The CISG
Cross-border sales between merchants in different countries are governed by the United Nations Convention on Contracts for the International Sale of Goods, commonly called the CISG. The treaty has 97 signatory nations, including the United States, China, and most of Europe. It applies automatically whenever a sales contract is made between parties whose businesses are located in different signatory countries, unless the parties specifically opt out.14United Nations Commission on International Trade Law. United Nations Convention on Contracts for the International Sale of Goods (Vienna, 1980) (CISG) Many businesses do opt out, choosing the domestic law of one party instead. When no choice-of-law clause exists, the CISG fills the gap.
The convention does not cover every sale. It excludes goods bought for personal or household use, sales by auction, sales of stocks and financial instruments, sales of ships and aircraft, and sales of electricity.15United Nations Commission on International Trade Law. United Nations Convention on Contracts for the International Sale of Goods Consumer transactions and these specialized categories fall outside its reach, so a merchant assuming the CISG covers every international deal they touch may be looking at the wrong rulebook.
Incoterms
To allocate shipping responsibilities and insurance costs, international traders rely on Incoterms, a set of eleven standardized rules published by the International Chamber of Commerce. The current version, Incoterms 2020, defines who pays for transportation, who handles customs clearance, who arranges insurance, and when risk of loss transfers from seller to buyer.16International Trade Administration. Know Your Incoterms Terms like FOB (Free on Board) and CIF (Cost, Insurance, and Freight) are shorthand for entire packages of obligations. Choosing the wrong Incoterm, or misunderstanding which one applies, can leave a party bearing costs and risks they never meant to accept.
Where These Rules Came From
Merchant law traces to the Lex Mercatoria, or Law Merchant, which took shape during the Middle Ages. Traders who gathered at European fairs needed a way to resolve disputes quickly, without waiting for land courts that had no understanding of commerce. They created their own tribunals, often called piepowder courts, staffed by fellow merchants who understood the realities of trade. These courts decided cases on the spot, applying a body of custom that was remarkably consistent across national borders. Over several centuries, central governments absorbed these customs into their formal legal systems, and in England Lord Mansfield wove merchant custom into the common law during the eighteenth century. The modern UCC is the descendant of those early principles of speed, fairness, and practicality.