Method for checking security imprints

A method of checking security prints by means of a graphic stringa) a visual capture of the serial number and its input via an input device (25),b) a visual detection of the postal value and input via the input device (25),c) visually acquiring the graphical symbols and input via the input device (25),d) the start of an automatic evaluation and signaling of the comparison result or display of at least part of the quantities recovered from the marking for manual checking by a verifier of the postal authority.