Simbox fraud allows criminals to avoid proper charges, causing financial losses for telecom operators, by disguising international calls as local ones. To do this, they use the following methods:

• Simbox: A device which holds many multiple SIM cards of local origin that are often prepaid and regularly rotated to avoid detection

• VoIP Routing: First, the international call is sent over the internet using Voice over Internet Protocol (VoIP) technology. This lets fraudsters avoid traditional fees and call routes

• Caller ID Spoofing: The Simbox manipulates the caller ID so that it appears as though the call is coming from a local number even though it’s international so that users and telecom systems are fooled into thinking it’s a local call

• Call termination: Next, the call passes through one of the local SIMs in the Simbox to enter the network as though it were a local call. it doesn’t get charged the proper rate because the telecom provider doesn’t recognise it as being international

Simbox fraud causes serious damage to telecom networks, operators, and customers, including impacts like:

• Revenue loss: Because it undercuts telecom providers and bypasses legitimate fees, Simbox fraud prevents revenue generated by international call rates. This can be particularly damaging in countries with high termination rates

• Poor Service Quality: Illegally routed calls often suffer from dropped connections, delays, and poor voice quality, which can be frustrating for real users experiencing these consequences

• Increased Security Risks: Fraud schemes such as Simbox fraud can mask criminal activity, causing a threat to national security and making it harder for operaters and law enforcers to trace calls and ensure secure connections

• Drains Network Resources: High volumes of test calls and spoofed activity congests networks and reduces efficiency for legitimate traffic

SIM box fraud can be identified using a combination of fraud management techniques, including data analysis and proactive monitoring. For example, it can be detected by:

• Spotting unusual call patterns, like high volumes of short calls or odd timing

• Identifying geographic mismatches where call origins don’t match expected locations

• Running random test calls to check for irregular routing or poor quality
• Monitoring gateway traffic to catch calls that bypass international routes

• Tracking voice quality issues such as call drops or delays caused by rerouting

Occam’s analytics tools bring these insights together to quickly uncover and prevent SIM box activity, helping you stay ahead of fraud and maintain customer trust.