Sometimes the question arises as to how long a will remains valid after its execution, or whether the witnesses have to be alive at the time it is probated. The short answer is that, provided the will was valid when signed, it is still valid years later. And witnesses do not necessarily have to be alive when the will is probated.
That said, some problems can arise with older wills, but those problems are easily taken care of by careful planning.
Wills that are self-proving will help in avoiding problems later on. And most wills actually are self-proving. If the will happens to not be self-proving, it will be more problematic to probate. To be self-proving, a will must have been executed by the testator and the witnesses. There must also be an affidavit stating that the will was signed freely, that it was intended to be the testator's will, that the testator was at least 18 years of age and of sound mind, without any undue influence, and before a notary public.
If the will is not self-proving, one of the witnesses, or some individual with knowledge of the execution of the will, must appear before the Surrogate court before the will can be admitted to probate and testify to the proper execution. The person who appears could be someone who can testify to the authenticity of the testator's and witnesses' signatures, or someone who witnessed the signing itself. If the will is self-proving, the witnesses have no need to be present at the Surrogates court in order to probate the will.
Along with ensuring that a will is self-proving, it is wise to periodically review your financial and familial situation and track changes in the law that may affect the way you wish to set up your will. Doing so will prevent you from having to make major last-minute changes. In consultation with an attorney, one can make necessary or desired changes while one still has the chance.
Source: Star Ledger, "Older wills can be difficult for heirs to resolve," Karin Price Mueller, 2 May 2011.