## Facts

- The case concerned a couple engaged to be married; prior to marriage, the woman agreed to relinquish claims to her fiancé’s estate upon his death in exchange for £600.
- At the relevant time, the fiancé’s estate was valued at £10,000.
- After the husband’s death, the wife sought to void the pre-marital agreement, claiming undue influence.
- The trial judge found in the wife’s favour; the deceased’s children appealed.
- The Court of Appeal upheld the original ruling, confirming the presence of undue influence.

## Issues

1. Whether a fiduciary relationship exists between engaged couples sufficient to ground a presumption of undue influence in pre-marital agreements.
2. Whether the lack of informed consent and independent legal advice rendered the pre-marital agreement voidable for undue influence.
3. Whether the transaction was so one-sided as to justify judicial intervention and the shifting of the evidential burden.

## Decision

- The Court of Appeal held that a fiduciary relationship is not automatic between engaged couples; its existence must be determined based on the facts and circumstances of the case.
- The transaction was deemed “extravagantly one-sided,” favouring the husband and creating a presumption of undue influence.
- The wife was not informed of the full value of the estate and did not receive independent legal advice when entering the agreement.
- The evidence did not rebut the presumption of undue influence, as there was no proof of “full, free and informed” consent by the wife.
- The agreement was set aside due to undue influence.

## Legal Principles

- A fiduciary relationship between engaged couples is not presumed; the court may find such a relationship where a transaction is manifestly disadvantageous to one party.
- For a presumption of undue influence to arise, there must be both a relationship of confidence and a transaction that is manifestly one-sided.
- When the presumption arises, the burden shifts to the benefiting party to prove that the agreement resulted from the other’s full, free, and informed thought.
- Lack of full disclosure and absence of independent legal advice undermines the validity of consent in such transactions.
- Courts are willing to scrutinize and set aside agreements where there is an imbalance of power and inadequate information or advice.

## Conclusion

The Court of Appeal in Zamet v Hyman established that pre-marital agreements may be set aside where undue influence is found, particularly if the agreement is excessively one-sided and entered into without full disclosure or independent advice, reinforcing the necessity for free and informed consent in contractual relationships.

Zamet v Hyman [1961] 3 All ER 933