Do I need a prenup in New Zealand?
In New Zealand, a contracting out agreement — commonly called a prenup — allows partners to override the default 50/50 property split under the Property (Relationships) Act 1976. Both parties must receive independent legal advice for the agreement to be valid (section 21). Without one, the family home, chattels, and any property acquired during the relationship will be divided equally after three years together, regardless of who paid for them or who owned them before the relationship.
If you’re moving in with a partner and you own a home, have a business, or expect an inheritance, a contracting out agreement is the only reliable way to protect those assets. The earlier you act, the simpler the process — and the easier the conversation.
What is a contracting out agreement?
A contracting out agreement is a legal contract under section 21 of the Property (Relationships) Act 1976 that lets partners agree on how their property will be divided if the relationship ends, instead of following the default equal-sharing rules. It’s the New Zealand equivalent of what other countries call a prenuptial agreement (prenup) or a pre-relationship agreement.
For the agreement to be legally enforceable, the Act requires that:
- It must be in writing
- Both parties must sign it
- Both parties must receive independent legal advice before signing
- The lawyer for each party must certify that they explained the effects and implications of the agreement
If any of these requirements are not met, the agreement can be challenged and set aside by the Family Court. This is why both parties need their own separate lawyer — one lawyer cannot act for both.
When should I get a contracting out agreement?
The most common situations where a contracting out agreement makes sense:
Moving in together when one partner owns the home. This is by far the most common scenario we see. Under the Act, once a property becomes the family home it is relationship property — even if one partner owned it outright before the relationship. After three years of living together, the non-owning partner is entitled to half. A contracting out agreement can protect the home owner’s equity while fairly recognising the other partner’s contributions.
Protecting an inheritance. An inheritance is initially classified as separate property under the Act. However, if it’s deposited into a joint account, used to pay down the mortgage, or spent on improvements to the family home, it can lose its separate status through intermingling. A contracting out agreement can ring-fence an inheritance regardless of how it’s used.
Business owners entering a relationship. If you own a business or hold shares, the value of that business acquired during the relationship is relationship property. A contracting out agreement can exclude the business from any future property division — giving certainty to both the business owner and their partner.
Second relationships. Partners entering a second relationship often want to protect assets for children from a previous relationship. A contracting out agreement can ensure that specific property passes to your children rather than being divided with a new partner.
Couples with unequal assets. Where one partner brings significantly more property into the relationship, a contracting out agreement can set out a fair arrangement that acknowledges contributions from both sides without defaulting to an equal split of pre-relationship assets.
What happens to the mortgage?
One of the most practical questions in any contracting out agreement is how to treat mortgage payments and living costs when one partner owns the home and both are contributing to the household.
Treating a partner’s contribution as rent is not a successful strategy — the courts have generally taken a dim view of arrangements that leave one partner with no equity after years of contributing to a household. The better approach is to build a formula into the agreement that recognises contributions proportionally.
In our experience, the most robust agreements use a scaling mechanism: as the relationship progresses and contributions grow, the non-owning partner’s share increases on a defined schedule. This approach is fair, transparent, and — critically — far less likely to be challenged by the court as seriously unjust.
“The best contracting out agreements aren’t one-sided documents designed to protect one partner at the expense of the other. They’re fair arrangements that both parties genuinely agree to — and that fairness is what makes them hold up. Taking a very hard line is misguided. An agreement the court considers unjust is an agreement the court will overturn.”
Andy Bell, Partner, Lane Neave (Legal 500 Asia Pacific Recommended Lawyer)
Can the court overturn a contracting out agreement?
Yes. Under section 21J of the Property (Relationships) Act 1976, the Family Court can set aside a contracting out agreement if giving effect to it would cause “serious injustice.” The court considers all the circumstances, including:
- The provisions of the agreement
- The length of the relationship
- Whether there are children of the relationship
- Any changes in circumstances since the agreement was signed
- The extent to which the agreement was unfair or unreasonable when it was entered into
This is why we always advise clients to build fairness into their agreements from the outset. An agreement that acknowledges both parties’ contributions, allows for changing circumstances (such as one partner leaving work to care for children), and uses a proportional formula rather than an all-or-nothing approach is far more likely to withstand court scrutiny.
Agreements can also be set aside if the procedural requirements weren’t met — for example, if one party didn’t receive independent legal advice, or if they were pressured into signing.
How to raise the topic with your partner
Suggesting a contracting out agreement can feel awkward — it’s easy for the other person to hear “I don’t trust you” or “I’m planning for this to fail.” Neither is usually true.
We often advise clients to come and talk to us before raising the topic with their partner. We can help you frame the conversation around practical protection rather than lack of trust, explain what the agreement actually does (and what it doesn’t), and give you valid, sensible reasons that are easy to communicate.
In practice, most partners understand the logic once it’s explained clearly. A contracting out agreement isn’t about expecting the worst — it’s about having certainty and avoiding a much harder conversation later if circumstances change.
Our contracting out team
| Lawyer | Location | Focus |
|---|---|---|
| Andy Bell — Partner | Wellington | Leads the practice. Extensive experience in contracting out agreements for home owners, business owners, and second relationships. Legal 500 Asia Pacific Recommended Lawyer. |
| Gabrielle Thompson — Senior Lawyer | Auckland | Relationship property specialist. Handles contracting out agreements for Auckland clients, particularly in high-value property situations. |
| Tanya Lavan — Senior Lawyer | Wellington | Family law specialist with expertise in contracting out agreements involving children and care arrangements. |
| Sarah Wadworth — Senior Lawyer | Wellington, Auckland, Christchurch | Serves clients across three centres. |
What does a contracting out agreement cost?
The cost depends on the complexity of the arrangement and the assets involved. A straightforward agreement for a couple moving in together where one owns the home will generally cost less than one involving trusts, business interests, or multiple properties.
Both parties need their own lawyer, so there are two sets of legal fees. We’re transparent about costs from the outset — we’ll give you an estimate after the initial consultation so there are no surprises.
We offer a free 30-minute initial consultation to assess your situation and explain your options before you commit to anything.
Frequently Asked Questions
Can I get a contracting out agreement after moving in together?
Yes. There is no legal requirement to sign a contracting out agreement before moving in together. You can enter into one at any stage of the relationship — before, during, or even after separation. However, the earlier you act the simpler the process, because there are fewer intermingled assets and contributions to account for.
What makes a contracting out agreement invalid?
A contracting out agreement can be set aside if either party did not receive independent legal advice, if the agreement was not in writing and signed by both parties, or if giving effect to it would cause serious injustice under section 21J of the Property (Relationships) Act 1976. Pressure, duress, or non-disclosure of assets can also be grounds for challenge.
Does a contracting out agreement cover KiwiSaver?
KiwiSaver that accumulates during the relationship is classified as relationship property under the Property (Relationships) Act 1976. A contracting out agreement can address how KiwiSaver will be treated, including excluding it from the equal-sharing regime or setting out a different formula for division.
Can I update a contracting out agreement?
Yes, and you should. Circumstances change — you may have children, buy property together, receive an inheritance, or one partner may leave work. A contracting out agreement should be reviewed and updated when significant changes occur. We recommend reviewing your agreement every few years or whenever a major life event happens.
Do both partners need separate lawyers?
Yes. The Property (Relationships) Act 1976 requires that both parties receive independent legal advice for a contracting out agreement to be enforceable. This means each partner must have their own separate lawyer — one lawyer cannot act for both. We can recommend experienced independent lawyers for your partner if needed.
Thinking about a contracting out agreement?
Book a free 30-minute consultation with our team — in person at our Wellington or Auckland offices, by phone, or by video. We’ll assess your situation, explain your options, and give you a clear idea of costs before you commit to anything.
Wellington: Level 3, Perpetual Guardian House, 99 Customhouse Quay, Wellington 6011
Auckland: Gabrielle Thompson — +64 9 306 8009
Phone: (04) 499 4014
Email: andy.bell@laneneave.co.nz
Last updated: March 2026