A retention period is the number of years that certain records must be kept before they can be destroyed. This period may be required by law or set based on other reasons, such as legal liability, customer service, or for financial reporting purposes. Once the retention period for a document has expired, there is usually a standard process for verifying that the document can indeed be destroyed, which gives management a last chance to shift the document into longer-term storage. If this option is not taken, then the document is destroyed.
Certain documents with special historical or legal value are never destroyed; that is, the retention period is not specified.