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Reporting centre for telephone number misuse

Are you bothered by ping calls or other nuisance calls? Please tell us that. RTR depends on your help in combating phone number misuse.

Publication of suspicious phone numbers and recent observations

Reporting Form

The disclosed date is used to take targeted measurements against phone number misuse. With your help, we can also make suggestions to the legislature if there is still a need for additional regulation.

Note on data protection: We use the date you provide only for the purpose listed above. If you give us personal data, we will delete it within two months.

More information on unwanted calls, emails and SMS

Manipulation of phone numbers

Telephone numbers can be forged relatively easily (see FAQ on the caller’s number). Operators have little opportunity to check whether the signalled number is correct or not if the manipulation did not take place in their own network.

From a technical point of view, the number of the calling telephone connection is not necessary for successfully establishing a telephone connection (this can be compared with a postcard on which you write the wrong sender or no sender at all and which is still delivered).

It is particularly annoying when your own phone number is used to harass other people:

Those affected receive countless calls from unknown people who complain about harassing calls (e.g. advertising calls) with the number of the affected person. If the harassing calls have not been made, calls are also made to the affected people because the harassed persons call back the unknown number on the display. This indicates that the phone number of the affected people is being misused by strangers (so-called call ID spoofing). These cases can be extremely unpleasant, depending on the number of calls received by those affected and e.g. also seriously disrupt business operations in companies.

A call with a fake phone number is illegal, which is why a written report can be sent to the telecommunications office, which is responsible for conducting any administrative criminal proceedings.

You can find the contact details for the telecommunications office on our website.

However, we point out that it will be difficult to identify the perpetrators. If the calls with a manipulated number are delivered from abroad, it will in fact not be possible to trace them back. A report is therefore unlikely to have any direct impact on the continued abuse of the telephone number of the affected person.

The situation in this area is therefore not satisfactory and there are no "patent remedies" as to how those affected can protect themselves against this misuse of their telephone numbers. In the short term, one can therefore only hope that the use of the affected number for such harassment of other subscribers will stop quickly.

A last solution can be to change the phone number, which of course always involves effort and inconvenience.

How can you avoid unwanted calls?

Handle your personal information and telephone number carefully.

Only pass on your phone number specifically to reputable companies.

Do not rush to give your consent to be contacted or called for advertising purposes. You can withdraw your consent at any time.

If you are already receiving unwanted calls, here are some ways to reduce it:

  • If in doubt, do not accept calls if you see an unknown number on the display! Do not call back! If the caller really wants to get in touch with you, he will contact you again.
  • Research the number displayed to determine which country the call could be from; If phone numbers are used improperly, it is easy to find relevant information on the Internet.
  • Most smartphones offer the option to block or reject calls from certain numbers. Some operators offer a so-called "selective number block". This is the option to block incoming calls to a specific number. Your operator is not legally obliged to set up such a "selective number block" for you.
  • For smartphones e.g. the software, "Call Blocker" can be recommended which automatically rejects uninvited callers.
  • With the frequently changing numbers of callers, however, these hints are of limited help. They also assume that the correct phone number is actually displayed, which is not always the case.


If you feel that your lifestyle is severely impaired by telephone harassment, in some circumstances even threatened or frightened, then do not hesitate to seek support. Contact the police or advice centers (e.g. the women's helpline on 0800/222 555 or via chat at

FAQ on number misuse