Last Will and Testament in New Zealand: 5 Mistakes That Make It Invalid (2026)

Why the Wills Act 2007 sets a strict baseline

Before the 2007 Act, New Zealand courts applied the Wills Act 1837 (UK). The 2007 reform modernised execution rules and introduced a judicial dispensation power under section 14, but that power is discretionary and expensive to invoke — the High Court will only cure a defective will if it is "satisfied that the document expresses the deceased person's testamentary intentions." Relying on section 14 means a contested hearing, legal costs often exceeding $15,000, and months of delay before the estate can be administered.

Getting execution right the first time is always cheaper.

Mistake 1: witnesses who share the benefit

Section 11(3) of the Wills Act 2007 does not invalidate the will itself if a beneficiary witnesses it — but section 12 voids any gift made to that witness or the witness's spouse, civil union partner, or de facto partner. The will stands; the beneficiary-witness simply loses their inheritance.

The problem surfaces regularly in family situations where an adult child witnesses a parent's will and is also named as a residuary beneficiary. Courts have no discretion to reinstate the gift under section 12. The only remedy is to re-execute the will with independent witnesses, or to apply to the High Court under section 14 if re-execution is no longer possible (the testator has lost capacity or died).

Practical rule: choose witnesses who have no financial interest in the estate and no relationship to anyone who does.

Mistake 2: signing the wrong page or in the wrong sequence

Section 11(2) requires the testator to sign the will "at the foot or end" of the document, or in a position that makes clear the testator intended the signature to give effect to the writing above it. Witnesses must sign "in the presence of the testator."

Two errors appear repeatedly in DIY wills:

• The testator signs the cover sheet or the attestation clause before the body of the will is finalised, leaving blank pages or alterations that appear after the signature.
• Witnesses sign in another room or at a later date, without the testator present.

Neither mistake attracts automatic section 14 relief. The court looks for evidence that the testator "intended" the partial execution to be complete, and where the sequence is wrong that evidence is hard to produce.

Mistake 3: lack of testamentary capacity

A will executed without testamentary capacity is void regardless of how perfectly it is signed. New Zealand courts apply the four-part test from Banks v Goodfellow (1870) LR 5 QB 549, confirmed in numerous High Court decisions including Re Watson [2002] NZFLR 825: the testator must understand the nature of the act of making a will, the extent of their property, the claims of persons who might reasonably expect to benefit, and must not be suffering from a disorder affecting those faculties.

Capacity is assessed at the moment of execution. A person with early dementia may have capacity on a lucid day; a person with advanced Alzheimer's will not. Wills challenged on capacity grounds go to the High Court in its probate jurisdiction, and proceedings can take two to four years.

If there is any doubt, the attending solicitor should make detailed file notes, ideally supported by a contemporaneous medical opinion. Where a will is executed without professional oversight, family members who later challenge it on capacity grounds have significant procedural leverage.

Mistake 4: undue influence or suspicious circumstances

The High Court may refuse to admit a will to probate if satisfied that execution was procured by undue influence — defined in New Zealand case law as coercion or pressure that overrides the testator's free will. Mere persuasion is not enough; the influence must have destroyed the independence of the testator's judgment.

Suspicious circumstances attract a higher standard of proof. Where a will is prepared by a beneficiary who takes a substantial benefit, or where the testator was in a position of dependency, the proponent must affirmatively prove that the testator knew and approved the contents of the will.

Common fact patterns that trigger challenge: the will was drafted by the main beneficiary; the testator had poor English or literacy; the testator was isolated from other family members in their final years; a carer or caregiver is the primary legatee.

Mistake 5: failing to account for Family Protection Act claims

Even a perfectly executed will can be "invalidated" in practical terms by a successful claim under the Family Protection Act 1955. Section 4 requires the court to ask whether the will makes adequate provision for the proper maintenance and support of a spouse, civil union partner, de facto partner, or child of the testator. The court's jurisdiction extends to stepchildren and, in some circumstances, grandchildren.

New Zealand courts take an increasingly expansive view of what "adequate" means. In Williams v Aucutt [2000] 2 NZLR 479, the Court of Appeal said the standard is objective, not what the testator considered adequate, and factors include the size of the estate, the claimant's needs and other resources, and the strength of the moral claim.

A will that leaves a surviving spouse with nothing while concentrating assets in the children of an earlier marriage is a near-certain target. So is a will that disinherits an adult child without explanation. The practical solution is to document reasons in a memorandum of wishes kept with the will — courts have repeatedly said they give weight to a testator's stated reasons even when they are not binding.

What the High Court can — and cannot — fix

Section 14 of the Wills Act 2007 gives the High Court power to declare a document a valid will notwithstanding non-compliance with section 11, if the document expresses the testamentary intentions of the deceased. Section 14 has been used to validate signed but unwitnessed documents, text messages, and email drafts. The applicant bears the burden of proof, and the court must be "satisfied" — a standard applied carefully. Courts have declined to cure documents where it was unclear whether the deceased regarded the writing as final rather than a draft, because section 14 requires evidence of testamentary intention, not merely a written expression of wishes.

The dispensing power is a safety net, not a licence to skip execution formalities.

Getting the document right from the start

A valid New Zealand last will and testament needs: the testator's full name and address; a clear revocation of prior wills; appointment of an executor; specific and residuary gifts; and proper execution under section 11. Guardianship appointments for minor children should be explicit. Testamentary trusts, if used, need to name trustees and set out the trust terms.

For straightforward estates, the forms-legal.com free New Zealand last will and testament template covers each of these elements with guided prompts. The template does not replace legal advice for complex estates — particularly those involving blended families, business interests, or assets held in trusts — but for a single person with straightforward asset distribution, it provides a structured starting point that meets the section 11 requirements.

Once the will is signed, store the original with your solicitor or with Public Trust, and tell your executor where it is. A will nobody can find after death is treated as if it never existed.

After the will: probate and the Administration Act

Even a valid will only takes effect once a grant of probate is obtained from the High Court under the Administration Act 1969. The executor files the will and a supporting affidavit, pays the filing fee (NZD 269 as at 2025, a flat fee regardless of estate size), and receives letters testamentary. Since September 2025, assets up to NZD 40,000 held with a single institution can be released without probate under s. 65 of the Administration Act 1969; below that threshold, informal administration is available.

If the will is challenged, the High Court may decline to grant probate until proceedings are resolved. An executor who distributes before probate faces personal liability for any resulting loss.

Practical checklist before signing

Before the testator picks up a pen:

1. Are both witnesses physically present in the same room?
2. Do either witnesses benefit under the will, or have a relationship to someone who does?
3. Has the testator read the full document and can they explain its contents in their own words?
4. Has each page been initialled, or at minimum numbered and read?
5. Has the testator signed at the end — not the beginning — of the document?
6. Has provision been made for the spouse, civil union partner, de facto partner, and any children who might otherwise bring a Family Protection Act claim?

Run through those six points and most of the common failures are eliminated before the ink dries.