The need to protect customers’ data and ensure confidence in the banking system has resulted in the initiation of diverse efforts to improve the security system of commercial banks. The security threat associated with the conventional security system of password and personal identification numbers led to Bank Verification Numbers (BVN) by commercial banks in Nigeria. This study thus investigated the effect of BVNs on the protection of customers of commercial banks in Nigeria. A self-administered questionnaire was collected from 150 respondents based on a purposive random sampling technique. The data collected were analyzed using the descriptive statistic technique of simple percentage, frequency, and chi-square. It was found that BVN was significant and effective in protecting commercial banks customer through the protection of transaction, bank account and boosting customers’ confidence in the banking system. It was further established that BVN through their biometric security and the anti-fraud system help prevent fraud, impersonation, and security breaches on customers’ accounts. This study implies that a BVN is an efficient tool in protecting customers’ data in the banking system. BVN mechanisms put in place to ensure the protection of consumers is effective in strengthening banks’ security systems and protecting customers’ information and funds. This study’s novelty lies in investigating BVNs on the protection of commercial banks customers. Studies have not been conducted in the subject area because BVN is a recent innovation in the Nigerian banking sector.