Processing of stacks of sheets of securities into bundles and packs of bundles

There is described a method for processing stacks of sheets of securities, especially banknotes, into bundles and bundle packs, said sheets each having an array of security prints printed thereon which array comprises M columns and N rows. According to this method, each stack of sheets is processed into M successive bundle groups of N individual bundles each and these M successive bundle groups are stored in M separate storage areas, which storage areas are vertically superposed, whereby each one of the M successive bundle groups is stored in a predetermined one of the M separate storage areas. Subsequent stacks of sheets are processed, whereby each one of the M successive bundle groups processed from said subsequent stacks of sheets is piled in the same predetermined one of said M separate storage areas as the first stack of sheets. When K stacks of sheets have been processed, each storage area contains a complete set of N bundle packs of K bundles each. There is also described a bundle collating system for collecting the bundles processed according to the above collating method.