Biometric verification has attracted attention recently because it is more secure than knowledge- or token-based verification techniques. Multi-modal biometric verification can provide even greater accuracy by combining several forms of biometrics. However, there are problems with the availability, usability and acceptability of the technique. In this paper, we take a new approach in proposing a multi-modal biometric system that enables users to select which biometrics they prefer to be matched at the time of verification. This system also reduces the number of inputs required by adopting a sequential test based on statistical methods. In addition, the accuracy of the system can be controlled according to the security level required. We demonstrated the effectiveness of the proposed system experimentally.