# Overview <Card title="Quick API Reference" url="/docs/premium-apis/sim-secure/quick-api-reference"> Explore Thingspace Security API endpoints </Card> ## About SIM Secure for IoT SIM Secure for IoT creates device-SIM pairings that protect against unauthorized data usage and network access. As connected device deployments expand, the risk of SIM card misuse increases proportionally. SIM Secure for IoT addresses this security challenge by binding each SIM card to its designated device. SIM Secure for IoT enables you to: - Protect IoT sensors, devices, and industrial equipment by establishing exclusive SIM-device pairings. - Block unauthorized devices from accessing your private network infrastructure. When SIM Secure for IoT is activated on a SIM card, it becomes permanently associated with its initial host device. Should the SIM be transferred to a different device, the security feature detects this unauthorized change and blocks network connectivity. Network access is only permitted when the SIM operates within its originally paired device. ### License Types SIM Secure for IoT offers four distinct license options for device assignments: - **Lifetime** – The SIM Secure Lifetime license provides permanent protection for the device's operational lifespan. Once applied, lifetime licenses cannot be removed or transferred. The skuNumber for Lifetime License is "SIMSec-IoT-Lt". - **Flexible** – The SIM Secure Flexible license allows dynamic assignment and removal from SIM cards as needed. This SKU is available for individual purchase. The skuNumber for a Flexible license is "SIMSec-IoT". - **Flexible Bundle** — The SIM Secure Flexible license supports dynamic assignment and removal from SIM cards. This SKU comes packaged with additional ThingSpace Services. The skuNumber for a Flexible Bundle license is "TS-BUNDLE-KTO-SIMSEC-MRC". - **Intelligence Bundle** — The SIM Secure Flexible license enables dynamic assignment and removal from SIM cards. This SKU is integrated with ThingSpace Intelligent Services. The skuNumber for an Intelligence Bundle license is "TSS-IOT-INTLG-TIERED-SIMSEC".