Measures, including methods, apparatus and computer software are provided for processing electronic tokens. An authorization request is received in relation to processing of an electronic token. An identifier for a user terminal associated with the electronic token, and an account, are determined on the basis of the authorization request. In some arrangements, a location query for the user terminal is performed on the basis of the determined identifier, whereby to determine a location of the user terminal on the basis of a proximity of the user terminal to one or more base stations in a cellular telecommunications network. In some arrangements, a challenge message is sent to the user terminal, to establish a confidence that the transacting user terminal is the designated user terminal. Processing of the electronic token in relation to the account is selectively authorized on the basis of the result of the location query or challenge response.