Contra Proferentem In New Zealand: The Risk Of Ambiguous Contract Terms

If you run a small business, contracts are probably part of your daily life. You might be sending quotes, signing supplier terms, onboarding customers, hiring contractors, or partnering with another business to deliver a project.

Here’s the catch: even if you’ve got a written contract, it won’t always protect you the way you think it does. If a clause is unclear or can be read in more than one way, a court may interpret that ambiguity against the party who drafted (or provided) the wording.

That principle is called contra proferentem, and it’s especially important for businesses using their own standard terms or templates. If you’re looking into how contra proferentem works in New Zealand, this article breaks down what it means in practical terms and what you can do to reduce your risk.

What Is Contra Proferentem (And Why Does It Exist)?

Contra proferentem is a legal interpretation principle that, in simple terms, means:

• if a contract term is ambiguous (it can reasonably be read in more than one way),
• the ambiguity may be resolved against the party who drafted the wording (or the party relying on it).

The rationale is pretty business-common-sense: if you wrote the clause (or you’re the one insisting it’s included), you’re usually in the best position to make it clear. So if there’s doubt, you may not get the benefit of the doubt.

For New Zealand small businesses, contra proferentem tends to come up most often when you’re using:

• standard form customer terms (especially online)
• supplier agreements or purchase terms
• consulting or professional services agreements
• limitation of liability clauses
• termination, payment, or scope clauses

Importantly, contra proferentem isn’t about “punishing” businesses. It’s about how unclear drafting is handled when there’s a dispute and the wording genuinely isn’t clear.

When Does Contra Proferentem Apply In New Zealand Contract Disputes?

In practice, contra proferentem in New Zealand is usually not the first tool a court reaches for. Courts generally try to interpret contracts in a way that reflects what the parties objectively intended, reading the agreement as a whole and in its commercial context (an approach reflected in New Zealand appellate guidance on contractual interpretation, including cases like Vector Gas Ltd v Bay of Plenty Energy Ltd and Firm PI 1 Ltd v Zurich Australian Insurance Ltd).

However, contra proferentem can become relevant when:

• the wording is genuinely ambiguous after applying ordinary interpretation principles, and
• one party is seeking to rely on that wording to gain a benefit or avoid a responsibility.

Some common situations where the risk goes up:

1) You’re Relying On An Exclusion Or Limitation Clause

If your contract says something like “we are not liable for any loss,” but it doesn’t define what “loss” includes, doesn’t clearly address how the clause operates alongside any mandatory statutory protections that may apply (for example, under consumer protection laws), or clashes with other parts of the contract, you’re more exposed.

Ambiguity in a limitation clause can be costly, because those clauses are often the difference between a manageable dispute and a serious financial hit. If you’re including a limitation of liability clause, clarity matters more than ever.

2) The Contract Is “Your Terms” (Not Negotiated Terms)

If you supply standard terms to customers (for example, in a proposal, onboarding email, or online checkout), and those terms weren’t materially negotiated, it’s easier for a court to treat the wording as “your drafting.” If a clause is unclear, you may wear that risk.

3) Key Commercial Terms Are Vague

Contra proferentem often bites when a contract tries to be “simple,” but ends up being unclear on core items like:

• what exactly you’re delivering (scope)
• when you’re delivering it (timelines, milestones)
• how changes are handled (variations)
• what triggers extra fees (out-of-scope work)
• what happens if something goes wrong (remedies, liability)

Small businesses often operate fast, and it’s tempting to rely on a short set of terms. The problem is: short isn’t always clear.

4) A Clause Conflicts With Another Clause

Even if each clause looks “fine” on its own, inconsistency across the document creates ambiguity. For example:

• a termination clause allowing immediate termination, but a notice clause requiring 30 days’ notice for “all” terminations
• a scope clause saying “monthly support,” but a schedule promising “unlimited support”
• a pricing clause stating fixed fees, but a variation clause implying time-based billing for changes

When disputes happen, it’s common for each party to point to the clause that supports their position. If the document doesn’t reconcile the conflict clearly, contra proferentem may work against the party who produced the wording.

Why Contra Proferentem Matters For Small Businesses (Not Just Big Corporates)

It’s easy to assume “contract interpretation rules” only matter in large commercial deals. But contra proferentem issues come up regularly for small businesses in New Zealand, because SMEs are more likely to:

• use templates that haven’t been tailored to their services
• copy and paste clauses from old contracts (sometimes from a completely different industry)
• make last-minute edits without checking the flow-on effect
• send quotes and proposals that don’t properly align with their terms

And when something goes wrong, it’s rarely a neat dispute about one sentence. It’s usually a wider commercial problem: delayed delivery, unpaid invoices, scope creep, customer complaints, or a relationship breakdown.

If your contract is unclear, you may face:

• reduced leverage in negotiations (because you can’t confidently point to a clear clause)
• difficulty enforcing payment if your invoicing, deposit, or late fee wording is vague
• unexpected liability if your exclusions/limits don’t clearly apply
• project blowouts if scope and variations aren’t clearly structured
• higher legal costs because the dispute turns into an argument about meaning, not facts

Put simply: if you’re the one drafting the contract, ambiguity is not “neutral.” Under contra proferentem, ambiguity can become a direct business risk.

How Do You Draft Contracts To Reduce Contra Proferentem Risk?

You can’t eliminate all contract disputes (people and projects are messy), but you can reduce the risk that unclear drafting will be used against you.

Here are practical ways to strengthen your contracts from day one.

1) Start With The Right Document For The Job

One of the most common causes of ambiguity is using the wrong style of agreement.

• If you’re providing services to another business, you’ll usually want a properly structured Service Agreement (with scope, fees, variations, timelines, IP, confidentiality, termination and liability sections that match how you actually work).
• If you run an online business, you’ll often need clear customer-facing Website Terms and Conditions that align with your checkout flow, delivery/refund model, and customer support process.

When you’re using the right “container,” it’s much easier to be clear (and consistent) throughout.

2) Define The Key Terms You’re Going To Argue About Later

If there’s one drafting habit that reduces ambiguity quickly, it’s defining your key terms.

Examples of terms worth defining include:

• Services (what you will do, and what you won’t do)
• Deliverables (what the customer receives at the end)
• Business Day (particularly if your deadlines depend on it)
• Confidential Information (what is protected and what is excluded)
• Intellectual Property (who owns what pre-existing materials and what is created during the engagement)
• Loss (if your limitation clause uses this term)

When definitions are missing, parties tend to argue based on their own assumptions. That’s where contra proferentem can creep in if you supplied the drafting.

3) Make Scope And Variations Impossible To Misread

Scope creep is one of the most common “silent killers” in small business service contracts. It also creates the perfect environment for ambiguity disputes.

Your agreement should clearly cover:

• what’s included in the base fee
• what is explicitly excluded
• how the customer requests a change
• how you quote/prioritise changes
• what happens to deadlines when a change is requested

If your scope is unclear and you try to rely on a general sentence like “additional work will be charged,” you’re setting yourself up for a debate about what counts as “additional.” That’s exactly the kind of ambiguity that contra proferentem arguments are made of.

4) Be Careful With Broad “Catch-All” Clauses

It’s tempting to include clauses that try to cover everything, such as:

• “We are not responsible for any delays for any reason.”
• “The customer must pay all costs we incur.”
• “We may terminate at any time.”

Overly broad drafting can cause two problems:

• it may be interpreted narrowly (or against you) if it’s unclear how it’s meant to operate; and
• it may create compliance risk if it conflicts with other legal obligations (for example, consumer protections or fair trading rules).

Clear, specific drafting is usually stronger than broad drafting that looks “tough” but is hard to interpret.

5) Check That Your Contract Is Actually Legally Binding

Contra proferentem only matters if the contract is enforceable in the first place.

If you’re not sure whether your quote, proposal, online checkout terms, or emailed “agreement” is binding, it’s worth tightening that up early. This comes back to the fundamentals of offer/acceptance and certainty of terms. Having a clear understanding of what makes a contract legally binding can help you avoid disputes about whether there even was a deal.

6) Get Your Terms Reviewed Before You Roll Them Out

If you’re using standard terms across multiple customers, a small ambiguity can multiply into repeated risk.

A tailored Contract Review is often the most efficient way to spot:

• unclear wording that could be read against you
• clause conflicts (including “hidden” inconsistencies)
• gaps between how you operate and what the contract says
• liability exposure you didn’t realise you had

This is one of those “do it once properly” steps that can save you a lot of time and stress later.

Common Clauses Where Contra Proferentem Causes Problems

If you’re checking your own terms, these are the areas where we often see ambiguity turn into a real dispute.

Limitation Of Liability And Exclusions

These clauses need to be internally consistent and match the commercial reality of your engagement.

Watch out for ambiguity around:

• whether the cap applies per claim, per year, or in total
• whether the cap applies to all types of liability or only certain types
• what categories of loss are excluded (direct vs indirect, consequential loss, loss of profit, etc.)
• carve-outs (for example, fraud, wilful misconduct, or breaches of confidentiality)

Payment Terms, Late Fees, And “When Payment Is Due”

Vague payment terms are a classic small business trap. If your contract says payment is due “within a reasonable time,” you’re inviting an argument about what “reasonable” means.

Clear drafting usually includes:

• deposit amount and when it must be paid
• invoicing milestones (especially for longer projects)
• payment timeframes (e.g. 7 days, 14 days, end of month)
• late fees (if any) and how they’re calculated
• your rights if payment is late (pause work, withhold deliverables, terminate, recover costs)

Termination And Notice

If termination rights are unclear, you may end up stuck in an unprofitable relationship longer than you planned, or facing claims that you terminated incorrectly.

Common ambiguity issues include:

• confusion between “termination for convenience” and “termination for breach”
• unclear notice requirements (how notice is given and when it takes effect)
• what happens to prepaid fees, partially completed work, or outstanding invoices

Confidentiality And Information Handling

Many business relationships involve sharing commercially sensitive information, pricing, processes, customer data, or product plans.

If you want your confidentiality protections to be enforceable, don’t rely on a vague one-liner. A proper Non-Disclosure Agreement (or a well-drafted confidentiality clause inside your main contract) should clearly define what’s confidential, how it can be used, and what happens if there’s a breach.

“Plain English” Contracts That Skip The Hard Parts

Plain English is great. But “short” isn’t the same thing as “clear.”

A one-page agreement can be perfectly drafted, but it still needs to cover the issues that commonly cause disputes in your industry. If it doesn’t, the gaps will be filled by assumptions, and ambiguity increases the risk of a contra proferentem argument later.

Key Takeaways

• Contra proferentem is a principle that can interpret ambiguous contract terms against the party who drafted or relied on them, which is why clarity matters if you use your own standard terms.
• In New Zealand, contra proferentem disputes often arise around limitation of liability clauses, unclear scope and variations, conflicting clauses, and vague payment or termination terms.
• If you’re the party providing the contract, ambiguity is a real commercial risk, because you may not get the benefit of the doubt if a dispute ends up in formal negotiations or court.
• You can reduce risk by using the right agreement for the relationship, defining key terms, tightening scope/variations, and avoiding overly broad “catch-all” wording.
• Contracts should reflect how you actually operate in practice, not just what “sounds standard,” especially if you use the same terms across many customers.
• A tailored review can help you identify unclear drafting early, before it turns into a costly dispute.

If you’d like help tightening your contracts, drafting clear terms, or reviewing an agreement before you sign, you can reach us at 1800 730 617 or team@sprintlaw.com.au for a free, no-obligations chat.