A validation scheme for use with a transaction card such as a calling card, et cetera, using personalized biometric profile data that is inherently coupled to the card owner/user. A configuration process is used for populating a profile database with sample voice or other biometric responses elicited from the owner/user in response to a plurality of questions relating to information uniquely linked to the user such as, e.g., name, age, hobbies, et cetera, or biometric responses such as fingerprints, retinal scans, and palm prints, or implanted ID chips. When a transaction is attempted using the transaction card, a determination is made if a voice profile validation is required for authentication. If so, a question from the plurality of questions used in the configuration process is randomly selected and directed to the user for a response. Access is provided only if a match between the response and corresponding sample is found. In a passive mode, the validation scheme may be utilized as an auxiliary fraud prevention scheme in addition to existing authentication systems.