A codicil is a document written in the same format as a Will. A codicil revises, alters, adds to, or further explains the terms of a Will that was previously executed. Like a Will, a codicil can either be formally executed or created in holograph form (regardless of which form was used in the original Will). Like a formal Will, a formal codicil must also be witnesses by at least two people who were present at the time of signing. The witnesses to a codicil do not have to be the same people who witnessed the original Will. For a codicil to be valid, it must have been written after the date of the most recent Will.