How Can I Make Verbal Promises Legally Binding? (2026 Updated)

You’ve probably been there: you have a quick chat with a supplier, a customer, a potential co-founder, or even a mate helping you out - and you agree on something important.

Then later, things get fuzzy. Someone remembers the promise differently, denies it entirely, or says “it was just a conversation”.

The tricky part is that in New Zealand, verbal promises can be legally binding - but proving what was agreed (and enforcing it) is often where the real problems begin. This 2026 update reflects the reality of modern business: deals are made in DMs, voice notes, Zoom calls, and quick phone conversations, and you need practical ways to protect yourself from day one.

Let’s break down when a verbal agreement is enforceable in NZ, when it isn’t, and what you can do to turn “we agreed” into something you can actually rely on.

Are Verbal Promises Legally Binding In New Zealand?

Yes - a verbal agreement can be legally binding in New Zealand if it meets the usual requirements of a contract.

That said, a verbal promise being “binding” and a verbal promise being easy to enforce are two very different things. Even if the law recognises the agreement, you may still struggle if you can’t prove:

• what the exact terms were
• who agreed to what
• when the agreement was made
• whether both sides truly intended it to be a real deal

From a business owner’s perspective, this is why we generally recommend getting important terms in writing - not because verbal agreements are always invalid, but because disputes usually turn into “your word against theirs”.

Common Situations Where Verbal Promises Come Up

Verbal promises often happen in situations like:

• agreeing on a price for a service over the phone
• a supplier promising delivery dates or stock levels
• handshake deals with a business partner about profit share
• a landlord verbally agreeing to a rent reduction or repairs
• a customer saying they’ll pay by a certain date

These arrangements might feel straightforward in the moment - but if the relationship changes (or money is on the line), you’ll want something more solid than memory.

What Makes A Verbal Agreement A Contract?

For a verbal promise to be enforceable as a contract, you generally need the same core elements as a written contract.

1) Offer And Acceptance

One person makes an offer, and the other person accepts it. The acceptance needs to match the offer - if the other person changes key terms, that’s usually a counteroffer.

Example: You say, “I’ll design your website for $4,000, delivered in four weeks.” They say, “Yes, we accept.” That’s clear offer and acceptance.

2) Consideration (Something Of Value)

Most contracts require an exchange of value - usually money for goods/services, or one promise in exchange for another promise.

Example: You provide marketing services and they pay your invoice. That’s consideration.

3) Intention To Create Legal Relations

The law usually expects that business discussions are intended to be legally binding. But informal conversations can still be debated - especially if someone argues it was “just a chat”.

This is one reason why even a short follow-up email can make a huge difference (we’ll get to that soon).

4) Certainty (Clear Terms)

The agreement needs to be sufficiently clear. If key terms are missing or too vague, it may be hard (or impossible) to enforce.

Common “certainty” issues include:

• no agreed price or payment method
• no agreed timeframes
• no clarity on scope (what’s included vs excluded)
• no clarity on who is responsible for what

Even if both people feel like they made a deal, a court may struggle to enforce something that wasn’t defined properly.

5) Capacity And Authority

The person making the promise must have legal capacity (and, in business contexts, authority) to enter into the agreement.

If you’re dealing with a company, a practical question is: was the person you spoke to actually authorised to agree to the terms?

If you want to reduce this risk, it helps to deal with a clear decision-maker, or ask for confirmation in writing from someone with authority.

When Are Verbal Promises Not Enforceable (Or Risky To Rely On)?

Even if verbal agreements can be valid, there are situations where relying on a verbal promise is especially risky - either because the law requires writing, or because enforcement becomes difficult in practice.

Situations Where Writing Is Commonly Expected

Some types of arrangements are typically documented because they involve:

• large dollar values
• long timeframes
• complex deliverables or staged payments
• ongoing relationships (like retainers or subscriptions)
• important risk allocation (like liability, warranties, indemnities)

In these cases, even if a verbal agreement exists, the lack of a written contract can create major gaps - like what happens if the project changes, the relationship ends early, or something goes wrong.

For service-based businesses, it’s often more effective to put a proper Service Agreement in place than to try to “patch” a verbal deal after a dispute starts.

Contracts That Need Extra Care

Some legal arrangements are more sensitive or technical, and a verbal promise may not adequately protect you - for example:

• business purchases and sales (where there are lots of moving parts)
• complex leases or property arrangements
• investment and capital raising deals
• arrangements involving intellectual property ownership or licensing

In those situations, the cost of getting it wrong can be far higher than the cost of documenting it properly upfront.

“We’ll Sort The Details Later” Is A Red Flag

If you’ve agreed “in principle” but haven’t agreed on the details, it’s easy to end up with a dispute about what was actually promised.

This often happens where someone relies on:

• a rough quote without clear inclusions/exclusions
• a verbal agreement that doesn’t cover variations
• a promise that depends on future events (“if it goes well, we’ll…”)

If you’re at the “in principle” stage, documenting what’s agreed so far (and what isn’t) can stop misunderstandings from escalating.

How Do I Prove A Verbal Agreement If Something Goes Wrong?

If you want a verbal promise to hold up when it matters, you need to think about evidence. This is where many people get stuck - not because the law refuses to recognise verbal contracts, but because they can’t prove what was said.

Helpful evidence can include:

• contemporaneous notes (notes taken at the time of the call/meeting)
• follow-up emails confirming the key terms
• texts/DMs where the other party acknowledges the agreement
• invoices and payment records
• draft documents exchanged between the parties
• witnesses who heard the agreement
• conduct (what both sides did afterwards that suggests there was a deal)

The Simple Follow-Up Message That Can Save You

One of the most practical steps you can take is to send a short follow-up message right after the conversation, like:

“Thanks for the call - just confirming we agreed I’ll deliver X by for $, with payment due . Let me know today if I’ve missed anything.”

If they reply “Yes” or even continue the conversation without correcting it, that can become powerful evidence of what was agreed.

Be Careful With Recording Calls

Some business owners ask: “Can I just record the call?” Recording conversations can raise privacy issues, and the rules can be fact-specific. If call recording is part of how you operate (for example, sales calls or customer support), it’s worth checking your compliance approach and disclosures - including how you store recordings and who can access them.

For a deeper look at this topic, Business Call Recording Laws is a useful reference point.

How Can I Make Verbal Promises Legally Binding In Practice?

If you want to be protected from day one, the goal isn’t just “make it binding” - it’s to make it clear, provable, and enforceable.

Here are practical ways to do that, depending on your situation.

1) Confirm The Verbal Deal In Writing (Even If It’s Short)

You don’t always need a 20-page contract to protect yourself. In many cases, a short written confirmation is enough to lock in key terms:

• who the parties are (full legal names)
• what is being provided (scope)
• price and payment terms (including GST)
• timing and delivery milestones
• how changes/variations will be handled

If you’re regularly selling services, having a proper set of standard terms (tailored to your business) can save you time and reduce disputes.

2) Use Quotes And Invoices That Point To Your Terms

If you send quotes or invoices, make sure they aren’t just numbers - they should point to your agreed terms and key conditions.

This is particularly important for:

• cancellation and late payment rules
• what happens if the customer changes scope mid-job
• limitations on your liability (where appropriate)

It’s also a good idea to ensure your statements about pricing, performance, timeframes, and deliverables are accurate - misleading statements can create real legal exposure under consumer law, including the Fair Trading Act 1986.

3) Put A Proper Contract In Place For Ongoing Or High-Risk Work

If the arrangement is ongoing, high value, or high risk, a written contract is usually the right move - because it doesn’t just prove the deal, it defines what happens when something goes wrong.

Depending on what you’re doing, this could include:

• a Service Agreement for client work
• a Supply Agreement if you’re buying or selling goods through a supply relationship
• a Non-Disclosure Agreement before you share sensitive commercial information

These documents also help prevent the “selective memory” problem - where each side remembers the terms in a way that benefits them.

4) Make Sure The Right Person Is Agreeing (Authority Matters)

If you’re dealing with a company, it’s worth checking whether the person you’re speaking to actually has authority to commit the business.

This becomes especially relevant for major decisions like:

• long-term supply commitments
• exclusive arrangements
• large discounts or special pricing
• waiving fees or agreeing to refunds outside standard policy

When in doubt, ask for written confirmation from a director or authorised signatory, or request that the agreement be signed properly.

5) Back Yourself With The Right Business Structure Documents

Sometimes the “verbal promise” issue is actually a business-owner relationship issue - for example, a co-founder says “don’t worry, we’ll split profits 50/50” or “you’ll get equity later”.

These are exactly the kinds of promises that can cause serious disputes down the track. If you’re building a business with someone else, it’s worth putting a formal Shareholders Agreement in place (and aligning it with how the company is set up).

Likewise, a tailored Company Constitution can help clarify decision-making, share transfers, and governance - which reduces the chance that informal promises end up driving formal outcomes.

What Else Should I Put In Writing To Avoid Disputes?

If you’re trying to avoid disputes around verbal promises, it helps to think bigger than a single agreement. Most “verbal promise” disputes happen because the relationship doesn’t have a clear legal framework.

Depending on your business, you might also want to document:

Employment Arrangements

If you’re hiring staff (even casually or part-time), you should have clear written terms. It protects both sides and reduces misunderstandings about pay, hours, duties, and termination.

For most businesses, an Employment Contract is the baseline document that prevents “but you promised…” issues later.

Privacy And Customer Data Handling

If you collect personal information (customer names, emails, addresses, health info, payment details), you need to think about privacy compliance under the Privacy Act 2020.

A clear Privacy Policy can reduce disputes (and complaints) about what you collect, how you use it, and who you share it with.

Refunds, Returns, And Customer Promises

Many customer conflicts start with verbal promises made by sales staff - like “yes, you can return it anytime” or “we guarantee it will work for your purpose”. If those promises go beyond your written policy, you may still be held to them depending on the circumstances.

Clear customer-facing terms, staff training, and written policies help ensure everyone is making promises your business can actually honour.

Key Takeaways

• In New Zealand, verbal promises can be legally binding if they meet the usual contract requirements (offer, acceptance, consideration, intention, certainty, and capacity/authority).
• The biggest issue with verbal agreements isn’t validity - it’s evidence and enforceability, especially when people later disagree about what was said.
• You can strengthen a verbal deal by confirming key terms in writing straight after the conversation (email or message), keeping notes, and saving relevant communications.
• For higher-risk or ongoing arrangements, a tailored written agreement (like a Service Agreement, Supply Agreement, or NDA) is usually the safest way to protect your business from day one.
• If the verbal promise is about equity, profits, or co-founder arrangements, it’s worth documenting the relationship properly with a Shareholders Agreement and company governance documents.
• Clear written documents across your business (including Employment Contracts and a Privacy Policy) reduce “you promised” disputes and help you operate more confidently.

If you’d like help putting your agreement in writing, reviewing what was promised, or setting up contracts that protect you from day one, you can reach us at 0800 002 184 or team@sprintlaw.co.nz for a free, no-obligations chat.