An addendum is a piece of additional information in a letter, contract, or report. For example, in a real estate purchase agreement, these additions can be in the form of financing requirements and property inspection requirements.
In the field of law, this term usually describes part of a new clause or information added to a legal document to change previous information. This additional new information can change the purpose and nature of documents substantially. This additional information can also change its scope and impact on the parties involved. Therefore, to be legally valid, each party will sign and certify that they declare acceptance of the new information added.