Premium rate numbers cost callers more than normal numbers. Part of that charge is paid to the service provider, which puts premium rate numbers at high risk of being exploited via traffic pumping, a type of telecom fraud in which bad actors artificially inflate traffic to their premium rate numbers. When done across countries, this type of toll fraud is known as International Revenue Share Fraud (ISRF).
Most businesses never need to call premium rate numbers, so by default Plivo blocks calls to all phone numbers with high-risk prefixes as a way to prevent unwanted charges.
Plivo has identified thousands of premium rate and high-risk prefixes. You can export a list of these prefixes from the Voice > Geo Permissions > High-Risk Permissions screen of the Plivo console. Plivo regularly updates this list based on factors such as the rates associated with the premium numbers, call patterns, and third-party trends.
What if my use case requires calls to high-risk numbers?
You can request activation of high-risk permissions for your account or a particular subaccount by contacting our support team and providing them with details of your use case. The validation process for disabling a premium prefix block for a specific account and use case can take 48 hours or longer. We make every effort to expedite this process.