An addendum is an additional document that is attached to a finished document, such as a contract, to modify, clarify, or nullify a portion of the original document. It is used to include supplementary information, such as additional terms, conditions, or provisions, and is typically used when parties wish to incorporate new details without disrupting the core elements of the original agreement. An addendum does not modify the existing terms of the contract but rather expands upon them. It should not be confused with an amendment of a contract, which alters the original terms and conditions of a contract by replacing a specific portion of that agreement. An addendum is usually used when the changes are relatively minor and do not impact the fundamental aspects of the contract. For example, adding a new product option, specifying additional delivery instructions, or including a non-material clause are all common circumstances for using an addendum. An addendum should be signed or executed with the same formalities as the original document, unless the original document states otherwise.