PCAOB standard number 3 talks mostly about the RETENTION OF AND SUBSEQUENT CHANGES TO AUDIT DOCUMENTATION.
14. The auditor must retain audit documentation for seven years from the date the auditor grants permission to use the auditor's report in connection with the issuance of the company's financial statements ( report release date ),
Important to note: A unique feature of the PCAOB standard is a requirement to retain documentation for incomplete engagements (for which no report was issued) for seven years after the cessation of audit work due to an auditor withdrawal or termination.
15. Prior to the report release date, the auditor must have completed all necessary auditing procedures and obtained sufficient evidence to support the representations in the auditor's report. A complete and final set of audit documentation should be assembled for retention as of a date not more than 45 days after the report release date ( documentation completion date ). If a report is not issued in connection with an engagement, then the documentation completion date should not be more than 45 days from the date that fieldwork was substantially completed. If the auditor was unable to complete the engagement, then the documentation completion date should not be more than 45 days from the date the engagement ceased.
Technological advancement- switch to computer based retention
Most large accounting firms have their own audit software where documents are uploaded and saved.
IT systems keep track of all emails and office instant messaging such as Microsoft communicator.
A warning for auditors of SEC issuers, however: Rule 2-06 of Regulation S-X requires retention of documentation beyond the requirements of PCAOB Standard 3, including all correspondence and memos in paper or electronic media; e-mails created, sent, or received in connection with an audit or related professional practice engagement; and engagement-related conclusions, opinions, analyses, and data,...