Transmission of telephone numbers

(1) Providers of publicly available number-based interpersonal telecommunications services that enable end users to establish outgoing connections must ensure that, when a connection is established, a complete nationally significant telephone number of the German numbering space is transmitted, and identified as such, as the calling party's telephone number. The telephone number must be assigned to the end user for the service in the course of which the connection is established. Telephone numbers for directory enquiry services, mass traffic services, or premium services, numbers for short code services, and the emergency numbers 110 and 112 may not be transmitted as the calling party's telephone number. Other providers involved in the connection may not alter transmitted telephone numbers.
(2) End users may set up and transmit additional telephone numbers into the public telecommunications network only where they hold a right of use in the corresponding telephone number and it is a telephone number of the German numbering space. By way of derogation from the first sentence, in the case of call forwarding, the transmitted and displayed telephone number of the caller may be set up as the additional telephone number. Telephone numbers for directory enquiry services, mass traffic services, or premium services, numbers for short code services, and the emergency numbers 110 and 112 may not be set up by end users as an additional telephone number and transmitted into the public telecommunications network. The Federal Network Agency may, after hearing the trade circles and consumer associations concerned, determine conditions under which setting up a foreign telephone number is permitted by way of derogation from the first sentence.
(3) All providers of publicly available telecommunications services involved in the connection must ensure that telephone numbers for directory enquiry services, mass traffic services, or premium services, numbers for short code services, and the emergency numbers 110 and 112 are not transmitted and displayed as the calling party's telephone number. They must terminate connections in which telephone numbers under the first sentence are transmitted and displayed as the calling party's telephone number.
(4) All providers of publicly available telecommunications services involved in the connection must ensure that a nationally significant telephone number of the German numbering space is displayed as the calling party's telephone number only where the connection is handed over from the German public telephone network. Where a connection in which a nationally significant telephone number of the German numbering space is displayed is handed over from a foreign telephone network, the providers must ensure that the point of entry of the connection into the German network is clearly marked internally within the network; the display of the telephone number is to be suppressed. Excluded from the first sentence is international roaming in mobile communications. Called parties must have the possibility of rejecting calls with suppressed telephone number display in a simple manner and free of charge.
(5) Subsection (1) applies correspondingly to providers of number-based interpersonal telecommunications services in the transmission of text messages via the public telecommunications network. By way of derogation from the first sentence, numbers for short code services and alphanumeric sender identifications are permitted where the sender is clearly identifiable to the recipient and no two-way communication is enabled thereby.