Some CCR registrants have recently received fraudulent letters in an attempt to compromise their TPIN. Your TPIN should be kept confidential. CCR personnel will NEVER ask you for you TPIN. If you believe your TPIN may have been compromised, immediately contact the CCR Help Desk at 1-888-227-2423 to obtain a new TPIN. The point of contact concerning these fraudulent letters is the Department of Transportation, Office of the Inspector General Hotline at 1-800-424-9071.

(Source: https://www.ccr.dlis.dla.mil/ccr/scripts/index.html)