A mobile terminal for capturing biometric data of a user, comprising: - a data memory which contains a credential that is specifically assigned to the user, wherein the credential identifies the mobile terminal as being authorised to capture and save the biometric data of the user, wherein the data memory contains a geographical area specification; - an authentication module for authenticating the user to the mobile terminal by means of authentication data assigned to the user and for authenticating the mobile terminal to the user by means of the saved credential; - a sensor (208, 210) for capturing biometric data of the user; - a localisation unit, which is configured to capture a current position of the mobile terminal while the biometric data are being captured; - a control unit, which is configured to capture the biometric data of the user automatically or semi-automatically by means of the sensor only upon successful mutual authentication of the user and the mobile terminal; - a check unit for automatically checking the authenticity of the captured biometric data; - wherein the control unit is configured to save the captured biometric data in the data memory in protected form only when the captured biometric data are authentic according to the check, wherein the captured biometric data are only saved in the mobile terminal when the current position which is captured while the biometric data are being captured is located within the geographical area specification; - wherein the authentication module is configured to authenticate an operator to the mobile terminal by means of further authentication data assigned to the operator; - wherein the control unit is configured to allow the biometric data saved in a protected manner to be read only in the event of a successful authentication of the operator, for transmission of the read biometric data to a security document. - a data memory which contains a credential that is specifically assigned to the user, wherein the credential identifies the mobile terminal as being authorised to capture and save the biometric data of the user, wherein the data memory contains a geographical area specification; - an authentication module for authenticating the user to the mobile terminal by means of authentication data assigned to the user and for authenticating the mobile terminal to the user by means of the saved credential; - a sensor (208, 210) for capturing biometric data of the user; - a localisation unit, which is configured to capture a current position of the mobile terminal while the biometric data are being captured; - a control unit, which is configured to capture the biometric data of the user automatically or semi-automatically by means of the sensor only upon successful mutual authentication of the user and the mobile terminal; - a check unit for automatically checking the authenticity of the captured biometric data; - wherein the control unit is configured to save the captured biometric data in the data memory in protected form only when the captured biometric data are authentic according to the check, wherein the captured biometric data are only saved in the mobile terminal when the current position which is captured while the biometric data are being captured is located within the geographical area specification; - wherein the authentication module is configured to authenticate an operator to the mobile terminal by means of further authentication data assigned to the operator; - wherein the control unit is configured to allow the biometric data saved in a protected manner to be read only in the event of a successful authentication of the operator, for transmission of the read biometric data to a security document.