The maker of a will, commonly known as the "testator," must draft the will in accordance with the state's probate code for it to be held as valid. Generally, these formalities exist so that a probate court can verify the authenticity of the will. When a will is admitted to probate court, the court examines the will to make sure it was made in compliance with state law.
Proving a Will
Among a probate court's many duties is to prove the validity of a will. After all, the term "probate" in Latin means "to prove." If a will contains abnormalities, or if it appears inauthentic, a probate court may declare it invalid. Generally, problems with a will, such as a testator's mental incapacity, duress or fraud, are brought to the attention of the probate court by the will's beneficiaries and/or the testator's heirs.
Although there are minor deviations in state law regarding will formalities, typically a will must be signed by the testator and two witnesses. Usually, witnesses are required to sign the will in the presence of each other and the testator. Their signatures symbolize acknowledgment of the testator being of "sound mind." That is, capable of understanding the impact of making a will. If a will lacks witness signatures, a probate court may declare it invalid as it's difficult to verify authenticity without proof the witnesses were present during the will's execution.
Self-proving affidavits are common in many states. These documents are usually signed during the execution of a will and attached to it. They are notarized and include an oath by each witness acknowledging their presence at the time of execution. Generally, if a will is not self-proved, one of the witnesses will be called to sign an oath in front of a probate court official indicating the will is authentic.
If a testator's heirs believe there are problems with a will -- usually as a result of being omitted from it -- they may challenge its validity in probate court. For example, if a testator unexpectedly disinherited his children in favor of an acquaintance, his children may contest the will in probate court and the court will hear testimony. Sometimes experts are called to testify before the probate court, providing opinion on matters that fall within their expertise. For instance, if heirs believe the testator's signature was forged, a probate court may call upon a handwriting expert to examine the signature and provide expert opinion as to its authenticity.