There is a big difference between moral and legal obligations. The High Court made that point in finding that mirror wills signed by a married couple did not impose on either of them a binding obligation not to change their bequests in future, save by their mutual consent.

The couple attended a solicitor's office and made mirror wills whereby each of them left the entirety of his or her estate to the other. The effect of the wills was that, when the second of them died, all that remained of his or her assets would pass in equal shares to their child and the husband's three other children from a previous marriage.

When the husband died, the wife duly inherited his estate. However, shortly before her own death, she made a new will bequeathing all that she owned to her child, cutting out her three stepchildren.

In challenging her final will, the stepchildren argued that the mirror wills were mutual in character. She and their father had bound themselves not to make any further wills without the other's consent. On that basis they contended that, on their father's death, the wife's mirror will was rendered irrevocable.

The solicitor who drafted the mirror wills testified that he had advised the husband that there was no guarantee that the wife would not change her will following his death. He recalled that the wife had given an oral assurance that she would not disinherit the stepchildren. The husband had stated that, after 45 years of marriage, he trusted the wife implicitly and that there was no way she would do such a thing.

In rejecting the stepchildren's case, a judge found that the wife was under a moral obligation not to disinherit them after their father's death. However, she was not subject to a legally binding obligation to that effect. The couple had not entered into a reciprocal agreement, amounting to a contract, that their mirror wills would be irrevocable and remain unaltered, save by mutual consent.

That may have been their common expectation and desire at the time, but that was not enough. Even if it could be said that the wife had promised that she would not alter her bequests, the husband had given no reciprocal promise. The wife was thus free to make a new will after his death.

Dismissing the stepchildren's appeal against that outcome, the Court found no error of law in the judge's decision. He was entitled to find on the evidence that there was no clear agreement between the couple that, in the absence of mutual consent to the contrary, their mirror wills would be set in stone.