SIM card

(Subscriber Identity Module card) A smart card that gives a cellphone its phone number and customer identity. Introduced in 1991 for GSM phones, most cards are removable. Satellite and LTE phones also use SIM cards. Activated by the cellular carrier, the SIM card contains a unique ID, authentication codes, network-specific data and the customer's phone contacts. See IMSI.

As long as users stay with the same carrier, they can generally switch their phone number and calling plan to a different phone by moving the SIM card. For travelers, prepaid SIM cards are available for unlocked phones, and phones that hold more than one SIM are also offered (see multi-SIM). In the early 1990s when cellphones were large, the first SIMs were the size of a credit card (1FF). See eSIM, SIM lock, R-UIM and smart card.

Mini, Micro and Nano SIM Cards

A SIM is a chip with contacts on cardboard. Used during the transition from Mini to Micro cards, Micro SIMs were placed in a Mini SIM form factor (right).

Size   Thick   Form SIM Card         (mm)    (mm)   Factor

  Full Size        86x54   .76    1FF
  Mini (Standard)  25x15   .76    2FF
  Micro            15x12   .76    3FF
  Nano             12x9    .67    4FF
  Embedded   6x9  up to 1

Mini SIM

This Mini SIM was removed and flipped over to show the contacts and the six pins they press against.

Open the Case or Slide Out the Tray

Access to a SIM card is either from the inside by taking the back off or by inserting a pin into the side of the phone that releases the tray. See SIM needle.

Prepaid SIM Cards

For travelers with unlocked Android and other GSM cellphones, prepaid SIM cards can be purchased.

Mini or Micro

A SIM card may come in both Mini and Micro SIM formats that can be punched out as required.

Copyright © 1981-2025 by The Computer Language Company Inc. All Rights reserved. THIS DEFINITION IS FOR PERSONAL USE ONLY. All other reproduction is strictly prohibited without permission from the publisher.

Mentioned in

References in periodicals archive

Etisalat and du will be the service providers for the new SIM card initiative, the first of its kind in the world.

Now, free SIM card for UAE visitors

The authority's announcement comes after General Directorate of Residency and Foreigners Affairs (GDRFA) in Dubai said tourists in Dubai can enjoy a free Sim card, complete with complimentary talk time and data, on their arrival at the airport.

Tourists to UAE will get free SIM cards

The CTD team also seized a large quantity of contraband material from their possession, including six laptops, 12 mobile phone scanners, three biometric machines, 400 forms with an NGO's insignia, two plain silicon ribbons, 1,700 SIM cards of various cellular service providers, 1,000 fingerprints imprinted on silicon ribbons, three bank scanners, duplicate CNICs of 2,600 persons, tracing paper, one computer scanner and 3,100 jackets of activated SIMs of various networks.

How a gang duped the biometric system to get SIM cards for criminals

According to him, if an agent engages in pre-registered SIM cards and is arrested, the culpability in such a case will extend to other players in the SIM registration value chain including the super agents.

Fraudulent SIM Registration Operators To Get 25-Year Jail Term a NCC

Earlier this month, the Philippine National Police (PNP) chief, Director General Oscar Albayalde, backed proposals to have phone users register their SIM card details to discourage trolling and bullying on social media.

Congressmen renew call for SIM card registration

The registration process requires the SIM card holder to present their identification or passport, as well as have their fingerprints taken.

New deadline for SIM registrations

SIM cards are a critical element in the value chain of mobile network operators (MNOs), and their security is non-negotiable.

EDCH showcases SIM card solutions at MWC

Sheriffs from the Monrovia City Court confiscated equipment and hundreds of SIM Cards from both network providers.

LTA busts SIM BOX fraudsters

"This is a dangerous trend that jeopardises the security of citizens in the country and must therefore stop," said Dr Wangusi at a press briefing yesterday.The law requires telecommunications firms or their appointed agents to register SIM card owners after noting down their full name, identity card number, date of birth, gender, physical and postal address.

Mobile firms given 2 days to switch off illegal subscribers

The 250 somoni fee consists of 215 somonis ($23) connection fee, 35 somonis ($3.7) - transfer of SIM card to balance of a mobile user.

Mobile users to pay almost $27 for SIM card in Tajikistan since Sept 1