If a telephone number is used unlawfully, the Federal Network Agency can intervene and take appropriate measures.

A number may be misused if

• you are put on hold under a chargeable number and your request is not processed.
• a company only provides a high-priced number as a telephone contact for contractual questions
• you receive a recorded message on the telephone which is intended to entice you to call back, e.g. by informing you of an alleged prize.
• you are confronted with harassing call behavior, e.g. advertising calls on Sundays and public holidays
• Confusing, missing or incorrect price information about the connection costs when dialing an expensive number (e.g. (0)900 numbers, (0)180 numbers).
• At the beginning of a telephone call after dialing expensive numbers or after dialing call-by-call numbers, no or an incorrect price announcement is given.
• No price announcement is made for the connection costs of the transferred call when the call is forwarded by a directory assistance service.
• In the case of a call to a (0)900 number, there is no forced disconnection of the connection on the network side after one hour.
• in postal advertising letters, the addressee is misled to a considerable extent with the purpose of submitting a reply under the specified call number
• you receive unsolicited advertising SMS or other electronic advertising messages via Messenger (for example, via Facebook, Whatsapp, SIMSme, Threema or Line).
• You receive e-mail spam in which telephone numbers are advertised (unsolicited advertising e-mails).
• You receive fax spam, i.e. unsolicited promotional faxes.
• you receive ping calls, i.e. calls where the phone has only rung briefly for the purpose of provoking a callback
• a cell phone or Internet dialer automatically connects you to expensive numbers from your connection
• your Internet router or telephone system has been hacked by a third party and as a result chargeable connections are generated, or
• you are billed for inexplicable items such as subscription services.

Proven illegal use of the telephone number can be punished, depending on the extent of the violation, by:

• reprimand or warning,
• ordering the disconnection of telephone numbers,
• Billing and collection bans,
• porting bans,
• business model prohibition, or
• Switching bans.

In order to combat number misuse, you should provide the Federal Network Agency with as detailed information as possible on the facts surrounding the number misuse. Existing documents such as itemized bills or screenshots of websites visited should be enclosed.