There are many ways to challenge the validity of someone's will; lack of due execution; lack of testamentary capacity; lack of knowledge of approval; fraud and undue influence. Advancing a claim that the deceased was unduly influence to make a will in the terms they did is very difficult and as such claims of this nature are rare.
What do you need to prove for a claim of undue influence?
As Sir J P Wilde said in Hall v Hall  "Persuasion is not unlawful, but pressure of whatever character if so exerted as to overpower the volition without convincing the judgment...will constitute undue influence, though no force has been either used or threatened."
Therefore the court needs to assess whether sufficient pressure was exerted that made the testator execute the will they did. It has long been established that merely persuading the testator is not enough. Undue influence is understandably an emotive claim that people robustly defend. There needs to be strong evidence that the testator was coerced which can be difficult to obtain as the individual who can provide the best evidence is unable to do so.
The latest successful undue influence claim
In the media recently there has been a report of a successful undue influence claim.
Ho Chin passed away in 2015. Under the terms of her will executed in 2011, she left her entire estate to her only son, Winston. Mrs Chin’s estate was relatively modest as her husband held the majority of the family's wealth. Mrs Chin's previous will, executed in 2009, provided for her share of the family's business to be split equally between her six children. In the letter of wishes which accompanied the 2009 will she stated “I have always been very fair to all my children as they all came from my womb…I am very happy that my only son, Winston, is the main beneficiary of the Chin estate. I also want to bless my five daughters with my share in the property.”
Two of Mr Chin’s daughters advanced a claim that she had been unduly influenced in executing the 2011 will. They claimed that after Mrs Chin had a stroke in 2009, her health deteriorated and she became very dependant on her husband and son which left her vulnerable to their influence.
The court held that Mrs Chin's father was a traditionalist and believed that the family wealth should only pass to male heirs upon death. The two daughters claimed that Mrs Chin, who was previously very resilient to this thinking and wished to treat her children equally, was 'worn down' by her husband and son's approach.
The judge found that Mrs Chin was unduly pressured by her husband and/or son and had eventually caved to their demands 'for the sake of a quiet life.'
The judge held that "It is clear in my judgment...that from a time shortly after his wife's stroke, [George] Chin began to put pressure on his wife to leave her share of Southchurch Road to the male line, and that Winston was aware of his parents' argument on the issue…What is not permissible is for the pressure to be such that Mrs Chin succumbed to it for the sake of a quiet life to the extent that it overbore her wishes."
As with cases of this nature, family members are embroiled in conflict with people taking sides and the relationship suffers as a result. It is always worth noting that Mrs Chin passed away in 2015 and the case has only now been resolved. The court always encourages parties to attempt to resolve their dispute prior to court for these very reasons.