Having your will drafted by a professional involves only modest expense and has the great advantage of reducing the risk of your bequests being successfully challenged after you are gone. In a case on point, the High Court gave full legal effect to a strong-willed mother's determination to leave nothing to her son.

By her final will, the woman bequeathed one quarter of her estate to her sister and the remainder to her daughter. Before her death in her late 70s, she also signed a deed by which she transferred her home – by far her largest asset – into a trust of which her daughter was the ultimate beneficiary. Her son subsequently launched proceedings, challenging the validity of both documents.

He contended that his mother lacked the mental capacity required to make either document and that she neither understood nor approved of their contents. He accused his sister of bringing undue influence to bear upon their mother and of having poisoned her mind against him.

Ruling on the matter, the Court noted that she had, about 25 years before her death, suffered serious mental health difficulties following the traumatic breakdown of her marriage. By the time she died, she had been diagnosed with multiple medical conditions, including Alzheimer's disease and diabetes. Her ability to speak and understand English, which was not her native tongue, deteriorated in the last few years of her life.

She had, however, at no point been assessed as lacking the mental capacity to make important decisions. A video of her, taken three years before she died, revealed a vibrantly alert, inquisitive and happy individual. Shortly before her death, she was able to decide for herself that she wished to be returned home from hospital in the knowledge that she would die there.

Crucially, the Court noted that neither the will nor the trust deed were home-made or DIY documents. They were professionally drafted by solicitors at her request and in the absence of her daughter. The solicitors concerned testified that both documents accurately reflected the clear instructions she had given them.

Dismissing the son's claims, the Court found that she was a woman who held strong opinions and knew her own mind. When instructing the solicitor who drafted her will, she forcefully expressed her wish that her son should inherit nothing. She was not at the time being treated for any disturbance or impairment of the mind and there was no evidence that she was suffering side-effects from medication. Given that the final will in fact reduced her daughter's inheritance – she had been her sole beneficiary under a previous will – it was inherently unlikely that she had subjected her mother to undue influence.

In also upholding the validity of the trust deed, the Court noted evidence that she particularly wished her son to have no claim on her home. The document's effect was explained to her as part of the independent legal advice that she received and the language barrier was not such that she required an interpreter.