A banknote validator having a housing, a validation sensor; and a banknote drive mechanism. The banknote drive mechanism may be arranged to transport a banknote from an input aperture to a stacking device. The banknote drive mechanism may delimit a first banknote pathway proximal to an input aperture, and a second banknote pathway proximal to the stacking device. A pivotable security gate arrangement may be included that is resiliently biased to project into the second banknote pathway.