All too often, people neglect to make a will during their lifetimes (in 2011, two-thirds of Brits didn’t have one), which can lead to protracted and bitter disputes between families and friends over who inherits what from a deceased’s estate.

An emerging trend has been for the contents of wills to be challenged in court; several high-profile cases of this kind in recent years have seen both successful and unsuccessful claims made on a number of grounds, including omission, duress and incapacity.

Do you want to challenge the validity of a will, but don’t know how to, and don’t know whether you’ll be successful? To find some answers, Your Money spoke to Keith Etherington, a specialist in contentious probate cases at leading law firm Slater + Gordon.

• Omission

People can often feel they have been unjustly ‘cut out’ of a will – whether this amounts to being overlooked outright, or being left a sum by a relative they feel is insufficient. While challenges of this ilkare prevalent, Keith believes most are doomed to failure before they’ve even been lodged.

“Many can feel unfairly treated in a will – but the courts rarely agree, because for them it’s not a matter of whether a will ‘seems’ fair,” Keith remarks. “Unless duress or incapacity can be established, then a court will assume as a starting point that a will was written freely and knowingly – and it can be nigh-on impossible for a claimant to disprove that.”

However, there are some situations in which a claim on the basis of omission has a chance of succeeding. Sometimes, a testator can enter an informal agreement with another – for instance, a grandparent offering to pay their grandchild a monthly sum for maintenance during their time at University – and this will not be reflected in a will. “These cases have a good chance of winning, because the dependency of an individual on the testator is obvious, and easily proven,” Keith says. “Nonetheless, it’s far better to save those who rely on you the kerfuffle of having to prove their dependency – you should regularly update your will, in line with changing circumstances. No matter how old you are, make sure your will reflects your situation and commitments at that particular point in time.”

• Duress

When a will is contested on the grounds of duress, the party challenging the will believes the testator was subject to undue influence, or coercion, when writing it. While claims of this nature as not necessarily doomed to failure, they again have fairly low success rates. “In effect, a claimant has to prove beyond reasonable doubt that a testator was forced at almost literal gunpoint to write a will that did not reflect their wishes – and/or that a testator was used as a ‘puppet’ by another party,” laments Keith.

Legislation in this regard is fairly antiquated, and demands that claimants must conclusively demonstrate that there is no other reasonable explanation for the contents of a will. Procuring irrefutable evidence for these claims simply may not be feasible.

“Sometimes, claimants will point a person in a position of trust – whether it is a friend, relative or close acquaintance (such as a doctor or carer) – receiving a significant share of the testator’s assets as an indication that a will was written under duress,” remarks Keith,” but the law presumes that they are blameless unless proven otherwise, no matter their position.”

However, if you feel a vulnerable testator has handed over assets unknowingly, or been manipulated into doing so, that is a different matter – and such claims fall under the category of ‘incapacity’.

• Incapacity

For a will to be valid, a testator must be of sound mind. The legal test for verifying the validity of a will was established in the 1870 case of Banks v Goodfellow, which states that a person must:

• understand that they are making a will, and the effect of it
• know the nature and value of their estate
• understand the consequences of including and excluding certain people under their will
• not be suffering from any ‘disorder of mind’ which may influence their views

If a will fails to meet all four tests, then it can be challenged on the grounds of a lack of testamentary capacity.

“Such claims can often not be easy to fight, but they are by far the most successful,” Keith states. “There are many circumstances in which a testator may bequeath assets to people they would not have done under normal conditions. Frequently, cases arise because a testator writes up a will during their last few months; they could be in hospital, under medication and/or in pain, which could affect their thinking, and the contents of their will as a result.”

“Similarly, if a testator has spent the last few months of their lives with a particular person, or people (and, perhaps, if a testator has written up a will at that person’s advising), they may be indirectly impelled to bestow a much more significant share of their estate on them than they would otherwise.”

However, for a case of this kind to succeed, it must be shown that the will did not meet the test (or, tests) at the time it was written; it’s not sufficient to demonstrate that the deceased person lacked one or more of these qualities at a different point. Furthermore, as with claims relating to omission and undue influence, the burden of proof is on the person alleging incapacity.

Keith believes that the difficulty of successfully challenging a will highlights the importance of having your will composed with the assistance of a professional. “While the obvious temptation is to save on cost, I urge people not to try writing a will themselves using a template, or a mail order will writing service – while a solicitor may charge you between £150 and £300 for professional will writing help, this figure pales into insignificance when compared with the sizeable legal bills your friends and relatives could run up if they were to challenge your will in court.”

Furthermore, Keith makes it clear that a successful challenge will almost always be worth it. “If you have a legitimate case, pursue it. The courts have wide-ranging powers to transfer assets, demand one-off lump sums and even set up regular payments. It’s unlikely you’ll regret lodging your claim.”