Codicil
A document that amends an existing Will rather than replacing it. Codicils must be signed and witnessed in the same way as a Will.
Codicils are useful for small changes: replacing an executor, adding a specific gift, updating a beneficiary's name. For larger changes, a new Will is usually clearer than a series of codicils.
A codicil is read alongside the original Will. A series of codicils can become difficult to interpret; we generally recommend a fresh Will after two or three codicils.