In a method for providing a one-time password for a user device belonging to a user, which password is intended to register the user device with a server, the server generates the one-time password using a cryptographic operation on the basis of a unique use identifier and transmits the password to the user device. The method provides a service provider with the possibility of tying additional conditions for registration to the one-time password and thus increases the flexibility of the service provider when configuring the services offered by the latter and increases security against manipulation.