In addition to regular, on-going shredding service, which you should have in place for the protection of your customers, employees and your-self, every six month to a year you should purge all your in house records to remove any that are no longer needed. It can be just as dangerous to have too much information as not enough.
Better Business Bureau (BBB), Professional Records & Information Services Management (PRISM), American Records Management Association (ARMA), National Records Center (NRC), International facilities Management Association (IFMA)