What is an addition or modification of a will called?

A codicil is a legal document that is used to make additions or modifications to an existing will. It allows a testator to update their will without having to create an entirely new document. This can include changes such as adding new beneficiaries, altering the distribution of assets, or revoking specific provisions.

A codicil must typically be executed with the same formalities as a will, which usually involves being signed in the presence of witnesses. This ensures that the changes are valid and legally enforceable.

In context, an amendment typically refers to changes made to a document, but in wills specifically, a codicil is the term used. A trust is a separate legal agreement for holding and managing assets, while an affidavit is a sworn statement of fact, neither of which pertain directly to the changes in a will.