There is presented a method, a computing device and a biometric matching service, for the biometric authentication of a user. The method comprises capturing a biometric sample from a user and obtaining information to identify data sources relevant to the user. The method further comprises using the data sources relevant to the user to obtain a plurality of biometric samples potentially captured from the user. The method further comprises matching the captured biometric sample against the plurality of potentially captured biometric samples to determine whether the captured biometric sample represents the user.