This test, whilst remaining good basic law, has given rise to considerable difficulties. Some of these are discussed by Peter Boynton in the Solicitor’s Journal – “The Last Litigation” - 27th September 2010. The article highlights some of the considerable difficulties which have arisen in recent cases :-
In the Estate of Key  EWHC Ch 408
Charles and others v Fraser  EWHC 2154
Perrins v Holland and others  EWCA Civ 840 – (here, the costs of the case exceeded the value of the estate).
These cases are not necessarily straightforward to understand without a good grasp of “succession law” but they show that it is essential for those who prepare wills to adhere to the relevant guidance and to be sure that the testator has testamentary capacity. Sometimes, medical opinion may be needed to assist with this – see BMJ “How to assess capacity to make a will” This is a difficult area of both law and practice.
Most consumers appear to think that all will writers are solicitors. This is far from the case – see Law Gazette January 2010. Unfortunately, will writing remains an unregulated activity and this makes it very important to be sure about the qualifications of anyone undertaking this work.
Interestingly, there is no legal requirement to register a will but it should be retained in a safe place. Many testators either leave the will with their solicitor or, often, it is simply kept somewhere at home. However, there is a registration service available – see here. This could be worth considering since some problems regarding “lost wills” might be avoided. It is only necessary to register the place where the will is kept.
See Law Society - Wills