Helping Retail Facing Telecommunications Operators To Stop Wangiri And IRSF To Over 12 Billion High Risk International Telephone Numbers

Wangiri fraud and IRSF have been around for years. They will continue to be around for as long as creative fraudsters can continue working together to set up clever methods of terminating calls to expensive but unallocated or unused destinations. They work behind the scenes and are making very good profits. The only real losers are the retail facing telecommunications companies and their unwitting customers.

Two of the main voice frauds of this nature are facilitated by either hacking into fixed line infrastructure to generate calls, or through Wangiri missed call scams.

These frauds will also continue to be facilitated if Telecommunications companies continue to adopt a retrospective monitoring approach using fraud management systems instead of a more proactive blocking approach.

The FNRM™ Preventative Blocking approach:

  • FNRM™ today lists over 60,000 unallocated or otherwise unused global number ranges where an operator would expect to see zero minutes for legitimate international terminating traffic.
  • All 60,000+ number ranges will default to prices within the price lists of International Carriers. The ranges with more expensive prices are the ranges where fraudsters target their efforts.
  • Biaas customers have proven that these 60,000 unallocated ranges can be implemented easily into switching and routing to ensure no calls terminate on these destinations.
  • The volume of number ranges is not far off that of the number of codes in a carrier price list, meaning it is a volume of codes that network teams will not easily shy away from implementing.
  • Implementing FNRM™ in this way will block 100% of calls to over 101 Billion possible international phone numbers that do not yet exist.
  • Most importantly, FNRM™ will also block 100% of calls to over 12 Billion possible international phone numbers that do not exist and are classified as ‘high risk’ in over 70 different countries. These are the exotic sounding destinations very much loved by fraudsters. Interestingly, the fraudsters can generate fantastic Answer Seizure ratios ( to attract even more traffic. This is because a human being does not answer the phone, since machine does it.
  • FNRM™ can of course also be used to block all incoming Wangiri missed calls which appear to be originating from one of the 12 Billion numbers.

Biaas will continue to actively develop and improve FNRM™, a database which has been continually evolving and improving since 2017, keeping up a pace to stay ahead of fraudsters.

The best tool we can recommend for identifying this ‘Intelligently Designed’ traffic is our Fraud Number Range Management database, FNRM™. You can read more about it on our website at