Retention requirements vary according to different laws. With respect to applications, the law requires you to keep all job applications of those who weren't hired for at least four years. Keep applications from those who are hired for the duration of employment plus four years. If you face a claim or litigation involving the hiring practice, keep the application for the duration of the claim or litigation.
You’re not required to keep unsolicited resumes or applications. Some employers send them back to the applicant along with a note explaining that there currently are no openings for the position sought. On the other hand, you can decide to keep unsolicited applications and resumes in a separate folder as a pool of candidates who wanted to work for you strongly enough to send resumes even though they didn’t know of a job opening.
Federal contractors have specific record-keeping requirements for Internet-based job applications. For more information, visit the Office of Federal Contract Compliance Programs’ website.