To endorse (or indorsement) is the writing of one’s name on part of an instrument as an authentication or transfer of an interest. Nowadays, the term endorsement is used to describe a writing anywhere on a negotiable instrument, contract, receipt, or other document requiring validation and authentication to signify that the endorser has received the document as presumably valid and authentic. Once a document has been endorsed, the rights and obligations in the instrument become valid or binding. Until the instrument is endorsed, the document remains unenforceable.
[Last updated in May of 2023 by the Wex Definitions Team]