A compact form factor integrated circuit card. In one embodiment, a Subscriber Identity Module (SIM) card is disclosed. In one embodiment, the SIM card has overall dimensions optimized for a particular application; e.g., 12.30 mm (±0.10 mm)×8.80 mm (0.10 mm)×0.67 mm (+0.03/−0.07). In another embodiment, the SIM card has overall dimensions of 11.90 mm (±0.10 mm)×8.80 mm (±0.10 mm)×0.70 mm (maximum). Multiple complementary SIM card adapters and methods of use are also disclosed.