What is an addition or abatement of a last will and testament called?

A codicil is a supplementary document that modifies, adds to, or revokes provisions in an existing last will and testament. It allows the testator, the person who created the will, to make changes without the need to rewrite the entire will. This is particularly useful when minor alterations are required, such as adjusting bequests, changing executors, or addressing changes in circumstances since the original will was executed.

A codicil must be executed with the same formalities as a will, meaning it typically needs to be signed and witnessed according to the laws governing wills in the relevant jurisdiction. This ensures that the changes are legally recognized and valid.

In contrast, an amendment is a broader term that can apply to any document and may not necessarily follow the strict formalities required for wills. Annulment refers to a legal declaration that a marriage is invalid and does not pertain to wills, while a declaration is typically a statement or announcement and does not have a specific legal function regarding altering a will. The specificity and legal framework surrounding codicils make it the correct term for modification of a last will and testament.