Abstract: The contracts litteris were solemn contracts, strict law and jus civile, following a number of written procedures, that created a new obligation or that transformed a preexisting obligation by recording of an abstract claim on behalf of a determined debtor . The appearance and use of this type of contract are direct consequences of the rules of private accounting, strictly regulated in ancient Rome, and the use of writing both as evidence and as the source of the obligation.

Keywords: contract formalism obligation, accounting, writing