# What is IRSF (International Revenue Share Fraud)?

> IRSF (International Revenue Share Fraud) is a telecom fraud in which criminals lease international premium-rate numbers and then generate artificial calls or messages to them, so the originating operator or business pays inflated termination fees while the fraudster and the number provider split the revenue.

- Canonical URL: https://www.broadnet.me/answers/what-is-irsf
- Language: en
- Last reviewed: 2026-10-20
- Publisher: BroadNet (https://www.broadnet.me)

## How does IRSF work?

International premium-rate numbers (IPRNs) carry an above-standard termination fee that is shared with whoever leases the range. Fraud starts when the traffic is generated artificially: the originating party — usually unaware — pays the inflated interconnect and settlement charges, and the payout to the fraudster is automatic. By the time the wholesale bill arrives weeks later, the money has moved down the settlement chain.

## Where does IRSF traffic come from?

Hacked enterprise PBXs that dial out overnight or over a weekend, SIM boxes and malware-infected handsets, Wangiri missed-call bait that tricks subscribers into calling a premium number back, stolen or fraudulently acquired SIMs used while roaming, and number ranges reserved for testing or not yet in service. In messaging, the same economics drive SMS pumping: automated sign-ups that trigger one-time passcodes to numbers the fraudster profits from.

## How do operators detect IRSF?

No single control stops it. Operators score traffic in real time against baselines for destination, duration, concurrency and time of day, screen destinations against databases of known premium and high-risk ranges, enforce credit, velocity and spend limits, harden PBX and SIP edges, and reconcile settlement data for sudden spikes towards obscure destinations.

## How can a business protect its OTP traffic from revenue-share fraud?

Rate-limit verification requests per number, per IP address and per destination country; block countries you do not serve; watch conversion from code sent to code entered; and use a number lookup to reject invalid or high-risk numbers before sending. BroadNet's operator-grade anti-fraud scoring and firewall controls baseline traffic across messaging and signalling, so anomalous traffic is held before it becomes a settlement liability.

## Related

- [All answers](https://www.broadnet.me/answers)
- [Glossary](https://www.broadnet.me/answers)
- [What is SMS pumping / artificial inflated traffic (AIT)?](https://www.broadnet.me/answers/what-is-sms-pumping)
- [What is AIT (Artificially Inflated Traffic)?](https://www.broadnet.me/answers/what-is-ait)
- [What is Wangiri fraud?](https://www.broadnet.me/answers/what-is-wangiri-fraud)
- [What is SIM box fraud?](https://www.broadnet.me/answers/what-is-sim-box-fraud)
- [How does telecom fraud prevention work?](https://www.broadnet.me/answers/telecom-fraud-prevention)
- [Anti-fraud SMS](https://www.broadnet.me/operators/anti-fraud-sms)
- [SMS Firewall (operators)](https://www.broadnet.me/operators/sms-firewall)