Letra has several different meanings in legal contexts in which it can rarely be rendered literally as “letter.” When describing a will (testamento), the expression escrito de puño y letra indicates that the document was “handwritten,” i.e., that it is a “holographic will” (testamento ológrafo). And when authenticating a document, cotejo pericial de letras denotes “expert handwriting analysis” conducted by a perito calígrafo (“handwriting expert” or “document examiner”).

In other respects, letra de cambio is a type of negotiable instrument, a “bill of exchange” (called a “draft” in the US). And Letras del Tesoro are “treasury bills,” the Spanish government’s short-term investment securities.