Corporate and Business Law (Global) · Obligations of the seller and buyer, and provisions common to both

Seller's Obligations under the CISG Explained

Updated 11 October 2026 · Fact-checked

Under the CISG, the seller must deliver the goods, hand over any related documents and transfer the property in the goods, as the contract and the Convention require. The goods must match the contract in quantity, quality, description and packaging, and must be free from third-party rights and claims.

Understand Seller's Obligations under CISG

The CISG is the UN Convention on Contracts for the International Sale of Goods. It sets default rules for sales between parties in different contracting states. The parties can change most of these rules in their contract. If the contract is silent, the Convention fills the gap.

The seller has three core duties. First, deliver the goods. Second, hand over documents relating to the goods, such as a bill of lading or invoice. Third, transfer the property in the goods. These come from Article 30. The seller must do each one as the contract and the Convention require.

Delivery depends on the contract. If the contract involves carriage of the goods, the seller delivers by handing the goods to the first carrier. If the contract does not involve carriage, and the goods are at a known place, the seller delivers by placing them at the buyer's disposal there. In other cases, the seller delivers by placing the goods at the buyer's disposal at the seller's place of business at the time of contracting. Time of delivery is the date fixed by the contract. If a period is fixed, it is any time within that period, unless the circumstances show the buyer chooses the date. Otherwise it is within a reasonable time after the contract is made.

The second half of the topic is conformity. The goods must be of the quantity, quality and description the contract requires, and must be contained or packaged as the contract requires. If the contract is silent, Article 35 gives default tests. The goods must be fit for the purposes goods of the same description would ordinarily be used for. They must be fit for any particular purpose made known to the seller at contracting, unless the buyer did not rely on the seller's skill or it was unreasonable to rely. They must possess the qualities of any sample or model the seller held out. They must be packaged in the usual manner for such goods, or, if there is none, in a manner adequate to preserve and protect them.

The seller is not liable under these Article 35 defaults if the buyer knew, or could not have been unaware, of the lack of conformity at contracting. The seller must also deliver goods free from third-party rights or claims, unless the buyer agreed to take them subject to those rights or claims.

Key formulas to remember

Core duties (Article 30): Seller must: deliver the goods + hand over documents + transfer property; All three must be done as the contract and the CISG require.
Place of delivery: carriage involved: Deliver by handing the goods over to the first carrier for transmission to the buyer; Applies where the contract involves carriage and no other place is agreed.
Place of delivery: no carriage, goods at a known place: Deliver by placing the goods at the buyer's disposal at that place; Applies where the goods are specific, or drawn from a specific stock or being made, and both parties knew where they were at contracting.
Place of delivery: other cases: Deliver by placing the goods at the buyer's disposal at the seller's place of business at contracting; The residual rule.
Time of delivery (Article 33): Fixed date, or any time within a fixed period, or else within a reasonable time after contracting; If a period is fixed, the seller may choose the date unless circumstances show the buyer chooses.
Conformity (Article 35(1)): Quantity + quality + description + contained or packaged as the contract requires; The contract comes first.
Default conformity tests (Article 35(2)): Ordinary purpose + particular purpose made known + sample or model + usual or adequate packaging; Apply only unless the parties have agreed otherwise.
Buyer's knowledge (Article 35(3)): No liability for defaults (a) to (d) if buyer knew or could not have been unaware of the defect at contracting; Applies to the Article 35(2) default tests, not to express contract terms.
Third-party rights: Goods must be free from any right or claim of a third party, unless the buyer agreed to take them subject to it; Intellectual property claims have a separate rule with extra conditions.

How to solve Seller's Obligations under CISG questions

Use the same sequence for any scenario question on the seller's duties. It keeps you from jumping to remedies too early.

1Confirm the CISG applies: international sale of goods, parties in different contracting states, and no exclusion in the contract.
2Read the contract terms first. Express terms on delivery, quantity, quality and packaging override the CISG defaults.
3Identify the duty in question: delivery, documents, transfer of property, conformity, or third-party rights.
4For delivery, decide place and then time. Ask whether carriage is involved, then apply the matching rule.
5For conformity, apply Article 35(1) express terms first. Only if silent, go through the four default tests in Article 35(2).
6Check whether the buyer knew of the defect at contracting, which can remove liability under the default tests.
7State your conclusion in one line: breached or not, and which duty. Leave remedies to the remedies topic unless asked.

Quickest way: Duty, place, time, conformity check

When to use it: Use this for Section A and Section B objective questions where you have about two minutes per question.

Spot the keyword: delivery, documents, title, quality, packaging, sample or third party.
If delivery: carriage means first carrier. No carriage and known location means that place. Otherwise the seller's place of business.
If conformity: contract terms first, then ordinary use, particular purpose, sample, packaging.
Scan for traps: buyer's prior knowledge, buyer did not rely on the seller, or the contract excluded a default.
Eliminate options that mix up the seller's and buyer's duties or that cite remedies when the question asks about duties.

Common mistakes in Seller's Obligations under CISG

Saying delivery always means the goods reach the buyer's premises.
Everyday meaning of delivery is arrival at the buyer's door.
Fix: Under the CISG, where carriage is involved, delivery is complete when the goods are handed to the first carrier.
Applying the Article 35(2) defaults when the contract already sets a standard.
Students memorise the four tests and use them automatically.
Fix: Express contract terms come first. The defaults apply only to fill gaps and where the parties have not agreed otherwise.
Ignoring the buyer's knowledge of the defect.
Focus stays on the seller's failure.
Fix: Check whether the buyer knew, or could not have been unaware, of the lack of conformity at contracting. If so, the seller is not liable under the default tests.
Forgetting the particular purpose test needs reliance.
Students remember only that the purpose was made known.
Fix: The seller is not liable if the buyer did not rely, or it was unreasonable to rely, on the seller's skill and judgment.
Treating packaging as a minor point outside conformity.
Packaging feels like logistics, not quality.
Fix: Packaging is part of conformity. Goods wrongly packed can be non-conforming even if the goods themselves are sound.
Mixing up seller duties with the buyer's duty to examine and give notice.
Both sit in the same chapter.
Fix: Answer the question asked. Seller duties concern what must be supplied. Buyer's examination and notice rules belong to the buyer's side and remedies.

Worked examples

Example 1

A seller in Country A agrees to sell 500 machine parts to a buyer in Country B. The contract involves transport by sea and states no place of delivery. The seller hands the parts to the shipping line at the port in Country A on 10 May. The parts arrive damaged on 30 May because of poor handling at sea. Has the seller failed to deliver?

Show the solution

The CISG applies: international sale of goods between parties in different contracting states.
The contract involves carriage and names no other place, so delivery is by handing the goods to the first carrier.
The seller handed the parts to the shipping line on 10 May, so delivery took place then.
Damage in transit from poor handling at sea is not a failure to deliver. Any question of who bears that loss depends on the rules on passing of risk, which are a separate topic.

Answer: The seller delivered on 10 May when the parts were handed to the first carrier. Damage during carriage does not mean the seller failed to deliver.

Example 2

A buyer tells the seller it needs industrial paint to coat marine equipment exposed to salt water. The seller supplies paint suitable for ordinary indoor walls. The contract describes only 'industrial paint' and says nothing on quality or use. The buyer relied on the seller's expertise. Did the seller supply conforming goods?

Show the solution

The contract is silent on quality and use, so the Article 35(2) default tests apply.
Ordinary purpose: the paint may be fit for ordinary purposes of industrial paint, but this is not decisive.
Particular purpose: the buyer made the marine use known at contracting and relied on the seller's skill. Nothing suggests reliance was unreasonable.
The paint is unsuitable for that purpose, so the seller breached the particular purpose test.
Check the buyer's knowledge: nothing says the buyer knew the paint was unsuitable at contracting, so the seller cannot rely on that exception.

Answer: No. The goods do not conform because they are unfit for the particular purpose made known to the seller, on which the buyer reasonably relied.

Exam tips

In objective questions, find the sentence that states the contract terms. If it sets a standard, the Article 35(2) defaults are a trap answer.
Learn the three delivery rules by their triggers: carriage, known location, everything else.
Look for words like 'knew' or 'inspected before signing'. They usually signal the buyer's knowledge exception.
In a six-mark multi-task question, name the duty, state the rule, apply it to the facts, then conclude in one sentence.
Do not cite Article numbers unless you are sure. Stating the rule in plain words earns the marks.

Practice questions from Obligations of the seller and buyer, and provisions common to both

Seller's Obligations under CISG: frequently asked questions

What are the seller's main obligations under the CISG?

The seller must deliver the goods, hand over any documents relating to them and transfer the property in the goods. The goods must also conform to the contract and be free from third-party rights or claims. These duties apply as the contract and the Convention require.

How does CISG Article 35 define conformity of goods?

Goods must match the contract in quantity, quality and description, and be contained or packaged as the contract requires. If the contract is silent, they must be fit for ordinary purposes, fit for any particular purpose made known, match any sample or model, and be packaged in the usual or an adequate manner.

Where must the seller deliver under the CISG?

It depends on the contract. If carriage is involved, the seller delivers by handing the goods to the first carrier. If not, and the goods are at a known place, the seller delivers there. Otherwise, the seller delivers at the seller's place of business.

Is the seller liable if the buyer knew the goods were defective?

Not under the Article 35(2) default tests. If the buyer knew, or could not have been unaware, of the lack of conformity at contracting, the seller is not liable for it under those tests. Express contract terms are treated differently.