The Universal Integrated Circuit Card (UICC) interface is also known as the Universal Subscriber Identity Module (USIM) or Subscriber Identity Module (SIM) interface. It consists of SIM_RST (pin 43), SIM_DET (pin 45), SIM_CLK (pin 46), SIM_IO (pin 48), and SIM_1V8 (pin 49).

nRF9160 supports UICC Class C interface with 1.8 V nominal voltage as described in ETSI TS102 221. If needed, support for higher supply voltage classes must be built with external components, including an external power supply and level shifters towards the UICC interface of the LTE modem.

The LTE modem controls the following physical interfaces towards the UICC and implements the transport protocol over the ISO/IEC 7816-3 interface: