Contracting out agreements and intestacies - the Supreme Court’s Rimmer v Wilton decision: three key takeaways

I suggest that people most at risk right now as a result of this decision (and with the most to lose) are those in longer term relationships with an old contracting out agreement in place that was signed some years ago and has not been reviewed or reconsidered since to update to present circumstances. 

The Supreme Court’s decision would have been a gut punch for any surviving partners who have suffered the death of a spouse or partner recently and have an outdated contracting out agreement still in place that may not properly reflect changes in circumstances or the shared life they have built together since the agreement was signed. In Rimmer v Wilton, the agreement at least left the surviving partner with a share of the property. There are plenty of contracting out agreements that leave one partner with nothing.  

Following the Supreme Court’s decision, the intestacy backstop that might have given them at least something is now gone. I do wonder if this decision could lead to a rise in people attempting to set aside old agreements on s21J (serious injustice grounds).  

The Supreme Court’s decision 

Rimmer v Wilton [2026] NZSC 122 was delivered on 4 September 2026. The Supreme Court held that a contracting out agreement under s 21 of the Property (Relationships) Act 1976 had displaced a surviving de facto partner's entitlement on her partner's intestacy. She received nothing from his share of the family home beyond what the agreement gave her, and was ordered to pay costs of $38,800. The agreement was signed in 2002. Mr Rimmer died in 2016.  

1.  Without a will, the agreement governs 

Under the Court of Appeal's reasoning, an agreement plus no will produced an intestacy. If partners did not wish to provide for each other from their estates, they needed to make wills gifting elsewhere (CA at [40]). 

The Supreme Court reversed the default. Mr Rimmer made no will and gave Ms Wilton nothing further, so “the Agreement still regulates the position” ([57]). Intestacy distributions are not the deceased's deemed intentions with the status of bequests; s 77 of the Administration Act 1969 applies where the deceased “has failed to express testamentary intentions” ([63]). 

Both courts reasoned from the same premise, that a party may always leave more by will. The Court of Appeal used it to conclude the agreement left intestacy untouched. The Supreme Court used it at [66] to conclude the opposite: precisely because a share could be bequeathed, s 21D(1)(c) contemplates an agreement defining what the survivor takes on the other's intestacy. 

What to do.  Any client with a contracting out agreement of some years' standing should be asked what the agreement actually provides on death, and whether that is still what they want. If they want their partner to have more, the agreement will not deliver it and intestacy can no longer be relied on to fill the gap. They need a will. Clients who signed an agreement in their thirties and have been together for fifteen years since are unlikely to have considered the question at all. 

2.  Broad release clauses now reach further than they were drafted to reach 

Clause 5.1 of the Rimmer agreement was a settlement of “all claims which each of them may have against the other under any statute whatsoever or at common law or at equity”. It did not mention the Administration Act, or intestacy, or death. 

The Court held that receiving an entitlement under the Administration Act involves making a claim under that Act, so the clause included it ([58]). Clause 5.1 was “a contractual promise by each party not to make any claims against the other's property”, and there is “no material difference between disclaiming and not claiming in this context” ([61]). Section 81(6) of the Administration Act makes contracting out possible ([59]). 

The Court of Appeal had said clearer words would be needed to override the mandatory terms of s 77. That was rejected as “unduly narrow” ([62]). 

What to do.  Full and final settlement type clauses appear in contracting out agreements in many forms, and no doubt most were drafted with separation in mind. Some name specific statutes, some do not. The Supreme Court was clear that outcomes turn on the terms of the particular agreement ([42], [55], [72]). But the Supreme Court essentially found that the absence of any specific exclusion of the Administration Act (ie the intestacy provisions) is no longer an answer. If an agreement is not intended to exclude intestacy entitlements, it now needs to say so expressly. On review of existing agreements, read the release clause as a clause about death and presume a broad release will cover claims under the Administration Act. 

3.  Section 21J is where the pressure now goes 

Intestacy has functioned as a backstop. Where an agreement left a surviving partner with little or nothing, the s 77 Administration Act entitlement, being the deceased's personal chattels, a prescribed sum of $155,000 and one third of the residue, meant they were not left with nothing at all. After Rimmer, that backstop is not there. Where the agreement provides nothing and the deceased left no will, the survivor may come away from a relationship of fifteen or twenty years with no share of the estate whatsoever. 

The likely consequence is more applications to set agreements aside. The Court preserved that route: ss 87 and 21J continue to apply whatever option is chosen under s 61, and an agreement may be set aside if giving effect to it would cause serious injustice ([71], [73]). For example, on grounds that the agreement has become unfair and unjust due to a change in circumstances. The longer the relationship the more time there is for such changes in circumstances to occur.  

The threshold remains high, and disparity of outcome alone has not been enough. But an outcome of nothing, after a long relationship, on an agreement signed a decade or more earlier and never reviewed, may well drive people to look at the s21J grounds and see if they can come within them – in an attempt to salvage something after such a long investment in their relationship cut short by an untimely death.  

Everyone with assets and responsibilities needs a will  

Finally, and related to point 1, every adult person with assets and responsibilities should have a will and should revise it periodically and whenever they have a life change.