A method of access by at least one second user, to at least one service offered by a first user is provided, which includes transmitting by the first user to the second user at least one invitation comprising an access level defined by the first user to allow said at least one second user to access said at least one service; verifying the content of said at least one invitation, delivering to the second user an access authorization to said at least one service, dependent on the access level; and requesting access to said at least one service by the second user, on the basis of the access authorization.