These minimal requirements must be met in most states:

• There must be some evidence that the testator (deceased) actually created the Will, and this can be proved through the use of witnesses, handwriting experts, or other methods.
• The testator must have had the mental capacity to write the Will, although such capacity is presumed unless there is evidence to the contrary.
• The testator must be expressing a wish to direct the distribution of his estate to beneficiaries.

Holographic wills are often created in emergency situations, and even states that don’t regularly recognize them have found them valid if an emergency existed at the time of the Will’s creation. Wills written by members of the armed services involved in armed conflicts and sailors at sea are often accepted as valid by courts in many states.

In the United States, unwitnessed holographic Wills are valid in nearly 30 states. Jurisdictions that do not recognize handwritten Wills may accept them under a "foreign wills act" if the Will had been drafted in a jurisdiction in which it would be valid.