What is a TWIC card? A TWIC card (Transportation Worker Identification Credential) can provide valuable advantages for a business involved in DOT drug testing, fingerprinting, and courier services, especially if the business operates in or services clients near ports, transportation hubs, or other secure maritime facilities. Reasons why you should have a TWIC card for your business: 🔐 1. Expanded Access to Secure Areas A TWIC card allows access to secure maritime facilities and vessels regulate