The toll-free phone number for the Transportation Worker Identification Credential, or TWIC, office in Houston, Texas, is 866-347-8942. TWICs are issued by the Transportation Security Administration.
The TWIC was created as part of the Maritime Transportation Security Act, as a way to prevent individuals who may potentially pose a security threat from gaining unescorted access to secure areas within the U.S. Maritime Transportation system. In Houston, a TWIC card is required for any individual who has a legitimate need to access the restricted areas at the Houston Port Authority terminals. The credential is not required for those who only need access to passenger areas.