phone number us postal service
1 Mail service issues [callers are then directed to 1-800-ASK-USPS (1-800-275-8777)] 2  Emergency situations (24/7 assistance) 3  Mail theft or identity theft issues, call 1-800-ASK-USPS (1-800-275-8777) 4  Mail fraud issues.  Postal Inspection Service customer support.