Certain legal transactions must be in writing to be valid. One is a transfer of land, another is making a will.

Unlike a transfer of land, a will can always be revoked and certain events do it automatically, for example, getting married.

What about after death?

There are a limited number of grounds on which to challenge the validity of a will. One is that the will was improperly executed. For this reason alone it would be a good idea to have your will at least checked by a solicitor.

Another challenge to a will might be that the person making the will did not have capacity. In other words did not understand what they were doing when they made the will. Challenges to capacity often involve elderly clients. Solicitors will generally ensure that an elderly client’s will is witnessed by their GP so that no difficulties arise later.

A further ground to set aside a will might be that it was made under duress. In other words coercion was used to persuade the testator to leave the properly to a particular individual. If it could be proved that Mr A had locked Mrs B in her bedroom and refused to let her out without a signature, a person challenging the will would have a good claim to set the will aside and the will would be void.

What about those others cases, however, where duress cannot be shown but some influence has been brought to bear on the person making the will which may have been, let’s say, inappropriate?

This brings us into the tricky area of undue influence. This must be distinguished from persuasion. Appeals to, for example, “leave the farm to me as you know I will make better use of it” are perfectly legitimate. It is the pressure put on the testator which affects her free judgement or wishes which gives rise to undue influence claims.

The courts have to consider the evidence and, if appropriate, draw inferences from that evidence. If the evidence is strong enough the court will conclude the testator was a victim of undue influence. The burden of proof is however high.

The cases are fact specific. The level of pressure which is required to overpower a testatrix’s free will often depends on the amount of willpower the testatrix actually has. It will take very little in the way of pressure to overpower a feeble person but if that person’s will is overpowered then that minimal pressure well be enough.

In the case of Gill v Woodall in 2009 the testator left her farm to the RSPCA and nothing to her only daughter. The request was set aside by the court and the court held “that Mrs Gill’s fear of the risk of Mr Gill losing his temper and then withdrawing his crucial support from Mrs Gill combined with her timid and shy personality, unduly influenced for her to make the will she did”.

In the case of Re Edwards, an elderly testatrix’s mind was “poisoned” by an alcoholic and violent son against another of her children.

The judge based his decision setting aside the will at least in part on the lies told by the son about his brother.

All of these cases must be confined to their exceptional facts. If a testatrix proposes putting something in their will which is out of the ordinary they should make their intentions known to family members especially if they will be disappointed.

If a family member is to receive less than they might expect the reasons for this should be explained.

This could be done with a letter left with the will. The testatrix should also be aware of the risk of giving hope even unintentionally to someone that they well benefit from their estate.