Probate, or proving, of a will can be made in common or solemn form. As noted at  in Young v Young “Probate in solemn form is generally irrevocable; probate in common form is revocable.”
By way of general observation probate in common form is what is most commonly sought. Probate in solemn form is appropriate where there are “contentious aspects of the will’s validity.”
Young v Young is interesting in that it invites the court to determine whether there will be probate in solemn form of a later will or probate in common form of the earlier will (which will not have been revoked if probate is not granted with respect to the later will.)
The case provides useful guidance regarding considerations as to validity. As noted at  the court does not need to know why a will was drafted, only “whether there is any foundation to doubt its validity.”
The will-maker in question was suffering from advanced dementia, as confirmed by her general practitioner. However, the witnesses to the will-maker’s signature gave evidence of her being engaged and responsive before signing the later will. This was contrasted against other contemporary evidence as to the will-maker’s loss of capacity.
Being satisfied on the balance of probabilities that the will-maker lacked testamentary capacity, the court found that the later will was not valid and accordingly that the earlier will was not revoked.
The case is useful for demonstrating the ability to address probate in solemn and common form in the same proceedings; and a reminder that a will-maker may be able to respond to historical prompts such as photographs, but nevertheless at the same time may not possess the requisite testamentary capacity to enter into a new will.
- Young v Young  NZHC 3397
- Wills Act 2007
- High Court Rule 27.4