New Zealand law provides for Pre-nups under Section 21 of the Property (Relationships) Act 1976 which expressly authorises that spouses, civil union partners, de facto partners may contract out of the Act.This means that you can decide how you want your property to be divided should you separate if you don’t want the provisions of the Act to apply. There are special requirements that must be met for Contracting Out Agreements (pre-nups) to be valid:
Provided that these requirements are met, it is very unlikely that a court will overturn a Contracting Out Agreement. Courts have held that people should be allowed to contract what they want and courts shouldn’t interfere with that. Courts have also held that because the couple have both received independent advice on the effects and implications of the Contracting Out Agreement, the court should uphold the agreement.
There are very special circumstances where the Contracting Out Agreement may be over-turned but this is very rare. Provided you have a good lawyer drafting the agreement and advising you on it, it is VERY unlikely that a court would overturn it.