• Gemalto is now part of the Thales Group, find out more.

SIM Cards


Let's discover the smart card contained in your GSM mobile phone (and in every mobile device).

SIM Card

What is a SIM card?

With a microprocessor base, a SIM card is similar to a mini-computer with its operating system, storage, and built-in security features. 

SIM is the acronym for Subscriber Identity Module.

When configured with up-to-date cryptography, as recommended by NIST, BSI, ANSSI, SIMalliance, etc., SIM cards provide a level of security that is state-of-the-art. 

The SIM card can add, delete and manipulate information within its memory, on top of sending and receiving data. 

A SIM card can be replaced by users and slides easily into a slot within your phone or mobile device. 

SIM form factors

SIM_Trio_with_format_name.pngDifferent form factors (FF) co-exist: 

  • The credit-card sized SIM is no longer used
  • A regular SIM or 2FF measures 15 millimeters by 25 mm 
  • A smaller version of the SIM called the micro-SIM or 3FF SIM card (Third Form Factor) is 12mm by 15mm
  • The nano-SIM or 4FF is 8.8 mm by 12.3 mm

Overall, according to Eurosmart, 5.56B secure elements (from SIM cards to eSIMs) will be shipped in 2019.

What is a SIM card used for?

Originally designed to access mobile phone networks, it authenticates the subscriber and ensures the user is accurately billed for used airtime. 

The SIM also stores your phone directories, messages, information on roaming across different networks and many other value-added voice and data services. 

End-users can instantly access news, games, chat and dating services along with mobile payment applications with an easy to use interface. 

It is not restricted by the handset model. This enables operators to reach all of their customers. 

SIM technology: key for operators

Operator-centered services such as call completion and automatic handset configuration help them reduce their customer billing costs and increase their Average Revenue per User (ARPU).

The SIM is the final link in the chain between networks and end-users and no customer can connect to the network without their SIM. 

Network operators can communicate, download applications, and manage a SIM card remotely using Over-the-Air (OTA) technology

For example, network operators can update the SIM cards with new applications and services without requiring users to upgrade their handsets or visit a store location.

Where do we fit in?

Gemalto is a major SIM card manufacturer and global solution and service provider.

Gemalto SIM cards provide interoperability and compliance with the latest standards, including new form factors such as the 4FF (Third Form Factor) or the eSIM (embedded SIM). 

This feature ensures that our SIM cards can connect to networks across the globe with any mobile phone or portable device (such as PDAs or Tablet computers). 

Gemalto also provides devices, software, and systems to manage everything from a single user's SIM card to an operator's entire distribution of SIM cards.

More resources

  • 5G SIM

    Definition & benefits of a 5G SIM for 5G virtualized networks

    Trust is increasingly perceived as a pervasive transversal factor to be added to virtualized 5G architecture in order to help to deliver the full 5G promises.

    Learn more

 BLOG

  • Posted on Jul 25, 2018

    3 reasons why eSIM is ready to make an impact in consumer IoT and M2M markets

    Learn about the most recent status of the eSIM following the announcements from the two main industry events

    Read this post