sentences:  The role of a national guaranteeing associations is to guarantee to its Customs administration the payment of duties and taxes due when ATA Carnets have been misused on its territory (non-or late re-exportation of goods, for instance).The national guaranteeing organisation can also, with the prior consent of its Customs administration, authorise local chambers to deliver ATA Carnets on its behalf.In major trading nations, dozens of local chambers have that authority.