One faulty delivery in a supply contract: dealing with instalment breaches in NZ

One defective shipment under a supply contract can feel like enough to walk away from the whole arrangement, especially when stock, cash flow and customer commitments are already under pressure. But under New Zealand sale of goods rules, that result is not automatic. Where goods are to be delivered by stated instalments and each instalment is paid for separately, the key question is whether the problem with one instalment is serious enough, in the context of the contract and the surrounding facts, to affect the whole deal or only that particular batch.

That distinction matters before you stop payment, refuse future deliveries or send a cancellation notice. A rushed response can create a second dispute about whether your business was entitled to reject only one shipment or whether it wrongfully treated the whole contract as over. This article focuses on domestic New Zealand business supply contracts for goods, not services or cross-border sales.

The rule is for stated instalments, paid separately

The specific rule sits in section 166 of the Contract and Commercial Law Act 2017. It covers defective deliveries by the seller, as well as a buyer neglecting or refusing to take delivery of, or pay for, one or more instalments. It does not apply to every ongoing commercial relationship.

For this rule to be in play, there must be a contract for the sale of goods that are to be delivered by stated instalments, and those instalments must be paid for separately. That wording is narrower than many people expect.

It usually points to a single supply contract that clearly breaks delivery into identified batches, lots or monthly quantities, with separate payment attaching to each batch. For example, a contract might provide for 12 monthly deliveries of packaging, each invoiced and paid separately.

That is different from:

• repeat purchase orders placed from time to time without one overarching instalment contract
• progress payments for services or mixed service arrangements
• a one-off sale with only one delivery date

The baseline position under the same Act is also useful. Unless otherwise agreed, a buyer is not bound to accept delivery by instalments. So if the parties are going to work on an instalment basis, the contract should make that structure clear.

In practice, the first job is classification. Before arguing about cancellation, check whether you are actually dealing with a stated-instalment goods contract, or whether the issue is simply a separate breach under one purchase order or one shipment.

Why one faulty delivery does not automatically end the whole contract

If the instalment delivery rule does apply, the Act says that whether the breach amounts to a repudiation of the whole contract, or instead is a severable breach that only gives rise to compensation, depends on the terms of the contract and the circumstances of the case.

That means there is no automatic rule that one defective instalment lets the buyer cancel every future instalment. There is also no fixed number of failures, no universal dollar threshold and no one-size-fits-all cure period built into this section.

The contract matters because the parties may have agreed to detailed quality standards, acceptance procedures, notice requirements, remediation steps, termination triggers or escalation rights. The surrounding facts matter because the same defect can have very different commercial effects in different supply arrangements.

Take these hypothetical contrasts:

A manufacturer contracts for 24 stated monthly deliveries of a specialised component, each batch paid for separately. The first defective batch shuts down production, and the contract says repeated or material specification failures may justify termination. If the defect also suggests the supplier cannot meet the agreed standard going forward, the issue may go beyond one shipment.

Now compare a contract for 24 monthly deliveries of standard cartons. One batch arrives with a small labelling defect affecting only part of the shipment, while the supplier offers prompt replacement and the remaining production history is sound. That may point more strongly to a batch-specific problem rather than a basis to treat the whole contract as repudiated.

These examples are only illustrations. The point is not that either result is guaranteed. The point is that businesses should resist the urge to treat every defective batch as an automatic exit right.

What parts of the contract should you review before sending a notice?

If you are thinking about rejecting a shipment, withholding payment or ending the whole arrangement, start with a careful contract review of the written contract and any documents that form part of it.

Look closely at:

• whether the contract actually describes stated instalments and separate payment for each
• product specifications, tolerances, testing criteria and quality benchmarks
• delivery timing, packaging and labelling obligations
• inspection and acceptance clauses
• notice periods for reporting defects
• repair, replacement or credit mechanisms
• express termination rights for repeated, material or uncured breach
• any clause dealing with suspension of future deliveries or suspension of payment
• priority wording between the master agreement, purchase orders and specifications

Also check the practical contract history. Under the Act, rights implied by law can be varied by express agreement, by the parties' course of dealing, or by a usage that binds both parties. That does not mean a business can simply write away every legal protection. It does mean the actual bargain and trading history can affect how a dispute is analysed.

For example, if both sides have repeatedly accepted minor quantity variances without complaint, that history may matter when assessing whether a later variance is truly treated as fundamental. Likewise, if the contract gives the supplier a defined replacement process for non-conforming goods, skipping that process may weaken a hardline whole-contract position.

Be careful not to overstate the Consumer Guarantees Act angle. The Contract and Commercial Law Act does not disappear just because the deal is business-to-business. One provision excludes only certain listed sale-of-goods sections where the Consumer Guarantees Act applies. It is not a blanket rule that every business purchase sits outside all consumer-style protections, and this article is not the place to assume a contracting-out position without reviewing the documents.

What evidence should you gather shipment by shipment?

If there is any chance the dispute could expand from one bad delivery to the future of the whole contract, the records matter almost as much as the legal wording.

A useful evidence pack usually includes:

• the signed contract and the operative version of any terms and conditions
• related purchase orders, specifications, statements of work or product schedules
• the instalment schedule showing quantities, dates and separate pricing
• invoices and payment records for each batch
• delivery dockets, warehouse intake logs and inspection records
• photos, test results and internal quality reports identifying the actual defect
• records showing whether the goods were accepted, partially accepted or rejected
• emails and messages about the defect, timing, replacement proposals and urgency
• any notices already sent about breach, suspension, rejection or termination
• evidence of what remains due under future instalments

Try to separate batch-specific facts from wider concerns. If your actual complaint is that a particular shipment was late, damaged or non-compliant, say that clearly. If you are also concerned that the supplier will not be able to perform the remaining instalments, identify the evidence for that concern instead of assuming it follows automatically.

That difference can be crucial. A business that bundles every complaint into one broad accusation can end up making it harder to see whether the real issue is one severable delivery failure or something that genuinely undermines the entire deal.

How should buyers and sellers respond without making the dispute worse?

For buyers, the immediate temptation is often to stop all payments and refuse every future batch. That can be risky if the contract and facts only support rejection of one instalment or a narrower claim for compensation.

For sellers, the equal risk is to insist that a bad batch was trivial without checking whether the defect points to a broader inability to perform the contract as promised.

A steadier response often looks like this:

• identify the exact instalment affected
• describe the defect precisely and refer to the contractual specification
• state whether the goods are being rejected, partially accepted or held pending resolution
• check whether the contract requires notice in a particular form or within a particular period
• ask what remedy is proposed for that shipment, such as replacement, rework or credit
• set out your position on upcoming instalments without assuming all rights are settled

That last point is especially useful. A buyer can say, for example, that it reserves its rights regarding future instalments while it reviews the contract and the supplier's proposed remedy. A seller can say it disputes any basis for whole-contract cancellation while proposing concrete steps to address the affected batch.

Neither approach guarantees the legal outcome, but both usually create a cleaner record than an angry email declaring the entire contract dead by close of business.

If goods have already been delivered, keep in mind that the Act also deals with examining goods and acceptance of goods. Whether goods were retained, used or otherwise dealt with can affect the position, so operational teams should be aligned with legal and procurement teams before the business acts in a way that may look like acceptance.

Hypothetical examples that show the real decision

Example one: A cafe group signs a twelve-month contract for stated monthly deliveries of branded takeaway cups, with each month's batch invoiced separately. Month three arrives with cups that leak because the lining does not match the specification. The buyer photographs the defects, keeps the affected stock separate, checks the contract's defect notice clause and notifies the supplier immediately. The supplier offers a replacement run within days. Here, the buyer still needs to assess whether the problem appears confined to month three or whether there is evidence that the remaining instalments will also fail.

Example two: A retailer agrees to buy six stated instalments of seasonal promotional stock, each separately priced. The second instalment is badly off-spec, and internal correspondence from the supplier already admitted production changes that will affect the remaining four deliveries. The contract also makes strict brand compliance essential. In that situation, the buyer would want advice on whether the overall contract position has shifted beyond a single defective batch.

Example three: A wholesaler is the seller under a stated-instalment goods contract. The buyer refuses to pay for one instalment, claiming defects, but warehouse records suggest the goods were received, used and not promptly rejected. The seller should gather the acceptance and use records before assuming the buyer can simply stop payment for that batch, let alone all future batches.

These examples all turn on the same practical point. The business should test its response against the contract and the evidence, not against a belief that one problem automatically answers the entire dispute.

Frequently asked questions

Can I cancel the whole supply contract after one defective delivery?

Not automatically. If the contract is for stated instalments paid separately, the issue depends on the contract terms and the circumstances. One defective batch may affect only that instalment, or it may have wider consequences, but you should not assume either result without review.

Does this apply to repeat purchase orders over several months?

Not necessarily. Repeated separate orders are not automatically the same as one goods contract for stated instalments paid separately. You need to look at whether there is one overarching instalment contract or simply a series of separate sales.

What if the contract says the supplier can fix defects?

That clause may matter a lot. If the contract sets out a repair, replacement or credit process, follow it carefully before claiming a right to end the whole arrangement, unless the facts clearly justify a broader position.

Can I withhold all future payments while we argue about one shipment?

That can be risky. Depending on the contract and the facts, withholding all future payments may itself become part of the dispute. Get tailored advice before taking that step.

Does this article cover overseas suppliers?

No. Cross-border sales can involve a different legal regime. This article is limited to domestic New Zealand goods supply arrangements.

Key Takeaways

• The instalment delivery rule in the Contract and Commercial Law Act 2017 applies to contracts for stated instalments of goods that are paid for separately, not every repeat commercial order.
• One defective delivery does not automatically let a buyer cancel the whole contract.
• Whether a breach affects the whole contract or only one instalment depends on the contract terms and the circumstances.
• Before rejecting future deliveries, stopping all payments or cancelling, review the contract's quality, notice, remedy and termination clauses.
• Build a shipment-by-shipment evidence pack covering the contract version, instalment schedule, separate prices, defects, acceptance or rejection records, correspondence and the obligations still outstanding.
• Get tailored legal advice before taking a whole-contract position, especially if the business plans to refuse all future deliveries or withhold all remaining payments.

If you are dealing with a disputed supply arrangement, our New Zealand legal team can help review your supply contract, assess instalment breach and termination wording, prepare a clear breach or response notice, and tighten your goods terms for future deals. Call 0800 002 184 or email team@sprintlaw.co.nz.