A phone number verification system was built using Spring Boot and the Twilio Verify API to provide an additional layer of security for businesses. The system generates a Time-based One-Time Password (TOTP) that is sent to the user's verified phone number, which can be used to authenticate users and prevent account takeovers. The system also includes endpoints to generate and verify TOTP codes, as well as handle errors and exceptions that may occur during the verification process. The system was tested using Postman and found to work correctly, with successful verification of the TOTP code and handling of incorrect or expired TOTP codes.