SIM full form

By Rebecca
2 Min Read

What is the full form of SIM?

SIM full form: Subscriber Identity Module or Subscriber Identification Module

SIM full form: A SIM is an integrated circuit that stores the International Mobile Subscriber Identity (IMSI) in a secure manner (IMSI). It’s a portable memory chip that lets you make and receive phone calls and text messages everywhere the subscriber’s network is available.

What is a SIM card, exactly?

A SIM card is a smart card that saves data for subscribers of GSM cellular phones. User identification, phone numbers, and whereabouts, network authorization data, personal security keys, address books, and archived text messages are examples of this type of data. SIM cards are widely used in GSM-enabled mobile phones. It is portable and may be used with any phone that supports it.

SIM Size

The initial SIM card was about the size of a credit card when it was invented. However, the most recent SIM standard was 15mm x 12mm in dimension. SIM cards are now available in three sizes:

  • Standard SIM (15 x 25mm)
  • Micro SIM (12 x 15mm)
  • Nano SIM (8.8 x 12.3mm)


Giesecke and Devrient, a Munich-based smart card manufacturer, invented the first SIM card in 1991. The European Telecommunications Standards Institute was the first to specify this SIM. SIM cards are already commonplace, allowing over 7 billion devices to connect to cellular networks all over the world.

What is the difference between a GSM SIM and a CDMA SIM?

You may remove the SIM card from a GSM phone. SIM cards are not commonly used in CDMA phones. Rather, all of the data is kept on the handset itself. Users may find this less convenient because they are unable to alter the service provider for that device.

Read more: PSI full form

Posted by Rebecca
Rebecca is an Independent content writer for breldigital, She writes content on any given topic. She loves to write a case study article or reviews on a brand, Be it any topic, she nails it