Collateral Contracts In New Zealand: When Pre-Contract Promises Bind

You’ve probably been here before: you’re negotiating a deal, the other side says something reassuring (maybe in a meeting, over email, or on a call), and you move forward based on that promise.

Then the “main contract” arrives… and the promise isn’t in it. Or worse, the written contract seems to contradict what you were told.

This is where collateral contracts can matter. In New Zealand commercial law, a pre-contract promise can sometimes become legally binding as its own separate contract - running alongside the main agreement - if certain requirements are met.

For small businesses, understanding collateral contracts is practical risk management. It can help you enforce key promises you relied on, and it can also help you avoid accidentally making promises you didn’t mean to legally guarantee.

Note: This article is general information for New Zealand businesses and isn’t legal advice. Because collateral contract disputes are very fact-specific, it’s worth getting advice for your situation before relying on (or disputing) a pre-contract promise.

What Is A Collateral Contract (In Plain English)?

A collateral contract is a separate, additional contract that sits “next to” the main contract.

It usually happens where:

• One party makes a specific promise or assurance before the main agreement is signed; and
• The other party enters into the main agreement in reliance on that promise.

In other words, the promise is the “extra deal” that convinces you to sign the “main deal”.

From a small business perspective, collateral contracts often show up in scenarios like:

• Buying a business where the seller promises key things about revenue, equipment condition, or supplier relationships.
• Signing a commercial lease where a landlord or agent promises certain works will be completed, or that you’ll be allowed a particular use.
• Engaging a supplier who promises certain performance levels, compatibility, or outcomes before you sign their standard terms.
• Service arrangements where a consultant promises specific deliverables or timeframes before you sign the formal scope.

Collateral contracts matter because they can give you a pathway to enforce a pre-contract promise even if it wasn’t included (or wasn’t clearly included) in the main written agreement.

When Can A Pre-Contract Promise Become A Collateral Contract?

Not every sales pitch, optimistic statement, or “we’ll look after you” comment creates a collateral contract. Courts look for the usual building blocks of a contract, plus a strong connection between the promise and your decision to sign the main deal.

While each situation is fact-specific, collateral contracts commonly depend on the following.

1) There Must Be A Clear Promise (Not Just Puffery)

The statement usually needs to be:

• Specific (e.g. “This machine can produce 1,000 units per day”), rather than vague (e.g. “It’s very efficient”).
• Promissory in nature (it reads like a commitment), not just an opinion or prediction.

As a business owner, a helpful way to sanity-check it is: “If this turns out to be untrue, would I reasonably expect I could hold them to it?” If yes, you should treat it as something that needs to be documented.

2) You Must Have Relied On The Promise When Entering The Main Contract

A collateral contract often hinges on reliance: you agreed to the main contract because the other side made the promise.

So, the closer the link between the promise and your decision to proceed, the stronger the argument. Practically, evidence of reliance could include:

• emails where you ask for confirmation and they reassure you;
• a written quote or proposal that includes the promise;
• meeting notes showing it was a key negotiation point; or
• drafts where you requested a clause and were told “don’t worry, we’ll honour that anyway”.

3) Intention To Create Legal Relations Must Be Present

In a commercial setting, there’s usually an assumption the parties intend to create legal relations - but that doesn’t mean every statement is intended as a contractual promise.

The more “deal-critical” the statement, the more likely it’s seen as legally serious.

4) Consideration Usually Exists (But It Can Be Easy To Miss)

Consideration is the “price” paid for a promise. In collateral contract scenarios, it’s often the act of entering into the main contract itself.

For example: “If you sign the supply agreement today, we promise the software will integrate with your system.” Your agreement to sign can be the consideration for the collateral promise.

5) The Promise Must Not Be Inconsistent With The Main Contract

This is a big one for small businesses: if the main written contract clearly contradicts the alleged collateral promise, it becomes much harder to argue there’s a binding collateral contract.

That said, “inconsistency” isn’t always straightforward. Courts will look closely at what was promised, what the written contract actually says, and whether both can sensibly operate together. If the written contract directly negates the alleged promise (rather than just being silent on it), a collateral contract claim is generally much more difficult.

That’s why it’s risky to rely on “side promises” where the final written agreement includes terms like:

• “You acknowledge you have not relied on any representations not set out in this agreement”; or
• “This agreement constitutes the entire agreement between the parties”.

Those clauses don’t automatically defeat every collateral contract argument, but they can be powerful evidence about what the parties intended to be binding (and what they intended to exclude). They can also affect what other claims may be available, depending on the facts.

Collateral Contracts Vs Misrepresentation: What’s The Difference For A Business Owner?

Collateral contracts often get mixed up with misrepresentation - and the difference matters because it can affect your remedies (what you can actually get from a legal claim).

In simple terms:

• A collateral contract is about a promise that becomes contractual. If it’s breached, you may seek contractual remedies like damages.
• Misrepresentation is about a false statement that induced you to enter a contract (even if it wasn’t a promise). Remedies can include damages and/or cancelling the contract in some circumstances.

Misrepresentation can arise under contract principles and under legislation like the Contract and Commercial Law Act 2017 (which consolidated various contract law rules). Depending on the situation, the Fair Trading Act 1986 can also be relevant if there was misleading or deceptive conduct in trade.

From a practical standpoint, if you’re unsure whether you’re dealing with a collateral contract or a misrepresentation issue, it’s usually a sign you should get advice early - because how you frame the dispute can impact your strategy and the outcome.

If you’re reviewing a disputed pre-contract statement, it can also help to understand the broader idea of misrepresentation, because the same facts can sometimes give rise to more than one potential legal pathway.

Common Small Business Scenarios Where Collateral Contracts Come Up

Collateral contracts aren’t just academic. They come up in everyday commercial decisions - especially when a fast-moving deal results in a “standard form” contract that doesn’t reflect the earlier discussions.

Buying Or Selling A Business

In business sales, purchasers often rely on what’s said during negotiations: customer numbers, average spend, stock levels, equipment condition, lease terms, and “handovers”.

If those assurances aren’t properly documented, disputes can arise after settlement (when it’s too late to renegotiate).

It’s one reason why a tailored Business Sale Agreement (and the disclosures that sit around it) matters - it should capture the promises that are truly deal-critical and avoid ambiguity about what was (and wasn’t) guaranteed.

Commercial Leases And Fit-Out Promises

A classic example is when a landlord or leasing agent says something like:

• “We’ll install new aircon before you move in.”
• “You’ll be allowed to operate as a takeaway.”
• “We’ll fix the plumbing issue.”

If the lease is signed but those promises aren’t in the lease (or are contradicted by the lease), you can be left with a serious operational problem.

For that reason, it’s smart to get a Commercial Lease Review before you sign - not just to check the rent, term, and outgoings, but also to make sure any “pre-contract assurances” are properly captured in the documents.

Supplier Quotes, Specs, And “It Will Definitely Work” Assurances

Suppliers often make performance claims during the sales process. The risk is that the final agreement might include:

• limited warranties;
• exclusions of liability;
• statements that you haven’t relied on representations; or
• a broad “entire agreement” clause.

If you’re signing up to important inputs (like equipment, software, packaging, or manufacturing), it’s usually worth ensuring the key promises are either:

• included as express warranties; or
• recorded in a signed scope/specification that is incorporated into the contract.

In many cases, that’s best handled through a properly drafted Service Agreement (or supply-style contract) rather than relying on pre-contract emails that might later be argued over.

Shareholder Or Founder Discussions Before Documents Are Signed

Early-stage businesses sometimes agree on “how things will work” before formal documents are in place - equity splits, roles, decision-making, restraints, and exit arrangements.

While collateral contracts can theoretically be argued in these contexts, relying on that is risky. The cleaner approach is to formalise the commercial deal in a Shareholders Agreement so everyone’s on the same page from day one.

How Do You Avoid Collateral Contract Disputes In Your Agreements?

The goal isn’t to “avoid” collateral contracts at all costs. Sometimes, they protect you when a promise you relied on was left out of the paperwork.

But as a business owner, you generally want certainty. You want your written contract to reflect the real deal - and you want to reduce the risk of “he said, she said” arguments later.

Here are practical ways to manage that risk when you’re negotiating commercial agreements.

1) Treat Pre-Contract Promises As Red Flags Until They’re Written Down

If a promise is important enough that you’re relying on it, it’s important enough to be documented.

That can mean:

• adding a clause to the contract;
• including it in a schedule (scope/specifications); or
• recording it in a side letter that is expressly binding.

If you’re the one making the promise, be careful about over-committing during negotiations. Your sales process should match what your business can actually deliver.

2) Use “Subject To Contract” Carefully

If negotiations are ongoing and you don’t want discussions to be binding yet, using “subject to contract” (and sticking to that position consistently) can help signal that nothing is final until the formal agreement is signed.

This won’t solve every problem, but it can reduce the risk of unintended obligations forming along the way.

3) Watch Out For Entire Agreement Clauses (But Don’t Rely On Them Blindly)

Entire agreement clauses are common, especially in standard terms. They aim to confine the deal to the written document.

From a risk perspective:

• If you’re relying on pre-contract promises, an entire agreement clause is a sign you should insist on inserting the promises into the contract.
• If you’re trying to avoid being bound by sales statements, an entire agreement clause can help - but it won’t necessarily prevent a collateral contract argument on its own, and it generally won’t protect you from misleading conduct issues under the Fair Trading Act 1986.

In other words: it’s a useful tool, but it’s not a magic shield.

4) Make Your Contract “Complete” (Schedules, Specs, Variation Process)

Many collateral contract disputes happen because the main contract is too thin. The “real detail” sits in emails, calls, or informal discussions.

You can reduce that risk by ensuring your agreement includes:

• a clear scope of works / specifications schedule;
• acceptance criteria (what counts as “done”);
• a variation process (how changes are agreed and priced);
• warranties that reflect what was promised; and
• liability and dispute resolution provisions that make commercial sense.

This is where a tailored Contract Review can save you time and cost later - it’s much cheaper to clarify the deal before you sign than to argue about it after something goes wrong.

5) Keep A Clear Paper Trail

If a dispute ever arises, evidence matters. Small businesses can protect themselves by keeping clear records of:

• quotes, proposals, and statements of work;
• emails confirming key points;
• meeting notes (even internal notes can help);
• contract drafts and tracked changes; and
• what you were told and when.

This doesn’t mean you need to turn every negotiation into a legal process - but you should capture the key commercial promises that affect price, timing, and deliverables.

Key Takeaways

• Collateral contracts are separate contracts that can arise from pre-contract promises that induced you to enter the main agreement.
• Not every pre-contract statement is enforceable - the promise usually needs to be clear, relied upon, and consistent with the main contract.
• Collateral contracts are often confused with misrepresentation, but they’re different legal pathways and can lead to different remedies.
• Common risk areas for small businesses include business purchases, commercial leases, supplier arrangements, and service contracts where key promises are made before signing.
• The best way to avoid disputes is to ensure the written contract reflects the real deal - especially for important promises about performance, timing, and deliverables.
• Entire agreement clauses and “subject to contract” wording can help manage risk, but they aren’t a substitute for properly documenting what’s been agreed.

If you’d like help reviewing negotiations, documenting key promises, or tightening up your commercial agreements so you’re protected from day one, you can reach us at 0800 002 184 or team@sprintlaw.co.nz for a free, no-obligations chat.