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What Information Is Stored On A SIM Card?
In today’s world, it is hard to imagine ourselves without communicating. We communicate when we call and send messages, share photos and videos on social media, even when we send corporate e-mails.
Two of the things that allow us to do this are cell phones and SIM cards. One is not useful without the other. A cell phone without a SIM card can work properly only under a Wi-Fi connection. On the other hand, there is no much to do just with a SIM card, right?
Since we already know how the basic features of a cell phone work, we think it wise to have a better understanding of SIM cards.
This time we will talk specifically about the information stored on a SIM card.
What is a SIM card?
A SIM card is also known as Subscriber Identity Module. It consists of a small chip that cell phones use to connect to a specific network. With a SIM card in your phone, you can make and receive calls, and send and receive text messages. Besides that, you can connect your cell phone to the internet using mobile data, which works excellent if you do not have a Wi-Fi connection.
The SIM cards usually come in three different sizes, which are Standard, Micro, and Nano. However, recently some cell phones and mobile networks have introduced e-SIMs to the market. It is an embedded SIM, which means you do not need a physical card.
The truth is that this small object can contain lots of information. You may imagine that it stores your contact information and data about your mobile network. However, there is much more inside the card. It can come in different capacities, from 32KB to 128K. Maybe it does not seem much, but it is enough to store all the information we will mention below.
Information Stored On A SIM Card
Advice of Charge (AoC):
This is a GSM (Global System for Mobile Communications) service, which estimates the costs of the mobile services.
Authentication Key (Ki)
It is unique for each SIM. It consists of a 128-bit value used to authenticate the SIM card on the network.
International Mobile Subscriber Identity (IMSI)
It is a number that identifies your SIM card within your mobile network operator.
Mobile Country Code (MCC)
It represents the first three digits of the IMSI number. Together with the Mobile Network Code (MNC), identify GSM networks worldwide.
Mobile Subscriber Identification Number (MSIN)
This number identifies a subscriber from a mobile network. It works as a link between the network and the user.
Mobile Station Integrated Services Digital Network (MSISDN)
It is the phone number you need to dial to establish communication. It can be changed if the subscriber requires it.
Local Area Identity (LAI)
This code works as an identifier and is composed of the mobile country code (MCC), the mobile network code (MNC), and a location area code (LAC).
Personal Identification Number (PIN)
It is a code used to lock and unlock the mobile device. The mobile operator provides it but it can be changed if necessary. It is usually made up of four digits, and can also be disabled.
Service Dialing Number (SDN)
They are numbers provided by the mobile operator, which the user can use to access services such as check current balance or voicemail.
Service Provider Name (SPN)
The name of your mobile operator.
Short Message Service Center (SMSC)
The service center that stores, processes and delivers your text messages (Short Message Service).
Unblocking Code (PUK)
This code is used when the user enters the wrong PIN code three times. The phone locks and asks for the PUK code that is provided by the mobile operator. If you enter the PUK code wrong more than 10 times, you will lock the SIM card without the chance of getting it back.
Integrated Circuit Card ID (ICCID)
It is a number that identifies a SIM card. It consists of an 18 – 22 digits code, which is unique for each SIM card in the world. There are not two SIM cards with the same information stored.
Value-Added Services (VAS)
It refers to additional services, which the customer use and pays for.
Another important things about SIM cards
SIM cards also store contacts. Nowadays, a SIM card of 128K of capacity can store up to 250 contacts. It is useful when you switch your phone because when you enter the SIM card into another phone, you will have your contacts. However, with the internet came services such as Google and Apple accounts. Now you can sync your contacts with your account, so you can have them anywhere on the internet.
As you can imagine, with a SIM card of 128K, there is no space for media such as photos and videos. That is why these types of files are stored in internal or external storage.
There is something called PIN code, which stands for Personal Identification Number. It is a code that allows the user to be sure no one else can use the SIM card. Each time you start your phone, it will ask you that code. As we mentioned before, if you enter the wrong PIN three times, it will ask you for the PUK code. It means that if a person gets to have your SIM card, they will not be able to use it without the PIN and PUK code.
Frequently Asked Questions
What does SIM stand for?
It stands for Subscriber Identity Module.
What exactly is a SIM card?
A small chip that contains information about your mobile carrier, and allows you to connect to a network.
What types of SIM cards are in the market?
You can find SIM cards in three different sizes: Standard, Nano, and Micro. Now there also e-SIM cards, which are embedded in the device.
Can I move my SIM card to a different cell phone?
Yes, you can insert the card into another cell phone, as long as it works with the same provider.
We hope that know you understand better what is inside that small chip on your phone. Even though it is pretty small, it can store loads of information!
