SIM

Technology & Computing abbreviation · Telecom

SIM
Stands forSubscriber Identity Module
CategoriesTechnology & Computing

SIM stands for Subscriber Identity Module, a telecom abbreviation.

Smart card in a mobile phone that stores the subscriber's identity and secret authentication key, linking the device to a carrier account and phone number. Moving the SIM moves the number to another phone.

Example: Put the local SIM in your phone when you land so you avoid roaming charges.

Usage notes

German company Giesecke+Devrient produced the first commercial SIM cards for the Finnish operator Radiolinja in 1991. Formats shrank from credit-card size to mini-SIM, micro-SIM (popularized by the iPad in 2010) and nano-SIM (iPhone 5, 2012). A SIM PIN protects the card, and the PUK unlocks it after wrong entries. Criminals use "SIM swap" fraud to hijack numbers and intercept security codes.

More telecom abbreviations

  • RF – Radio frequency
  • RFID – Radio-frequency identification
  • RJ11 – Registered Jack 11
  • RSSI – Received signal strength indicator
  • SAR – Specific absorption rate
  • SDR – Software-defined radio
  • SMS – Short Message Service
  • T1 – Transmission System 1
  • TDD – Time-division duplex
  • TDMA – Time-division multiple access
  • TTY – Teletypewriter (Unix terminal)
  • UC – Unified communications

See all 114 telecom abbreviations →