1. A method for testing the authenticity of documents wherein a document is tested by authenticity criteria, comprising providing at least two different authenticity classes each with one or more authenticity criteria for a valid document, the individual authenticity classes differing in at least one authenticity criterion, so that requirements for authenticity vary in strictness depending on the authenticity class, determining fitness or denomination of the documents; selecting an authenticity class from the different authenticity classes in dependence on the determined fitness or denomination of the document, testing the document by the authenticity criteria of the selected authenticity class, and assigning the document the selected authenticity class if the document meets the authenticity criteria thereof; wherein if the authenticity criteria of the selected authenticity class are not met, a further authenticity class with lower requirements for authenticity is selected and the authenticity testing repeated by the authenticity criteria of the selected further authenticity class.
11. The method according to claim 1 , wherein the documents are inputted by a depositor and supplied to authenticity testing, and data identifying the depositor and characteristic data of the inputted documents are stored together.