When a Property Relationships Agreement Decides Who Inherits

Rimmer v Wilton and the agreement that outlived its makers

On 4 September 2026 the Supreme Court delivered a decision that changes how contracting out agreements work on death. Rimmer v Wilton holds that a couple can, by agreement, give up the right to inherit from each other on an intestacy, and that in this case a widely used "full and final settlement" clause, read with the rest of the document, did exactly that. If you have a contracting out agreement in a drawer somewhere, its effect on your estate may not be what you were told, or what you assumed.

The decision matters for two quite different groups of people, and the advice is close to opposite for each. For couples who wanted their agreement to settle everything, this is welcome confirmation. For a surviving partner who signed a similar clause expecting to still inherit, it may be an unwelcome surprise.

What happened

David Rimmer and Carolyn Wilton began living together in September 2000. They bought a property at Moumoukai Road, Hūnua, together, as tenants in common in equal shares. In June 2002 they signed a contracting out agreement under section 21 of the Property (Relationships) Act 1976.

The agreement did the usual things. It set out what was separate property and what was relationship property. It said that if they separated, the relationship property would be divided in proportion to what each had contributed. It gave the survivor a lifetime right to occupy and use the relationship property if one of them died. And it contained a clause saying the agreement was in full and final settlement of all claims each might have against the other under any statute, at common law or in equity.

Mr Rimmer died in March 2016. He left no will. His estate was about $150,000 in cash and investments, some personal effects, and his half share of the Hūnua property, which was the main asset. He was survived by Ms Wilton and by his two adult children.

Ms Wilton was appointed administrator of his estate. She paid herself the cash entitlements the intestacy rules provide for a surviving partner, took his personal chattels, and transferred his share of the property to herself as administrator. She continued living in the house rent free until it sold in May 2021 for $1.2 million.

Her position, in short, was that she was entitled to her own share of the house under the agreement, and to a further slice of Mr Rimmer's share under the intestacy rules, because he had left no will. The High Court agreed with her in 2023. The Court of Appeal agreed with her in 2025. The Supreme Court has now unanimously disagreed.

What the Supreme Court decided

The Court held that reading the life interest clause together with the full and final settlement clause made the position clear. Ms Wilton's entitlement to the property was limited to her own share, plus the lifetime right to occupy Mr Rimmer's share. She had no further claim on his half. The clauses together amounted to what the Court called a comprehensive disentitlement to a beneficial interest in the other party's share, and it was plain those terms were meant to regulate the position after death. A clause confirming that the agreement bound each party's executors and administrators further confirmed the point.

Three points from the reasoning are worth drawing out.

1. You can contract out of inheriting on an intestacy. The Court confirmed this is legally possible, endorsing the approach two earlier High Court decisions had taken but which had never been tested at appellate level. Nothing in the Administration Act prevents it, and the Property (Relationships) Act positively contemplates couples defining what each will be entitled to on the other's death.
2. Taking an intestacy entitlement is making a claim. The Court of Appeal had thought a "claim" was an inapt description of an inheritance that simply arrives by operation of statute. The Supreme Court held that reading was unduly narrow. Receiving an entitlement under the Administration Act involves making a claim under that Act, so a promise not to make claims catches it.
3. Intestacy is not a substitute for a will. Ms Wilton argued the intestacy rules reflect what the deceased would probably have wanted, so the distribution to her should be treated much like a gift he had chosen to make. The Court rejected that. The intestacy rules apply precisely because the deceased failed to express any testamentary intention. Mr Rimmer expressed no intention to give her his share. On the contrary, he had agreed with her that she had no entitlement to it.

The Court was careful to say that none of this stops a couple choosing the opposite outcome. Mr Rimmer could have left his share to Ms Wilton by will, or transferred it to her while he was alive. Either would have worked, and receiving both an entitlement under the agreement and a gift under a will is not double dipping. He simply did neither.