What information is stored on a SIM card?
SIM, or subscriber identity module, cards are the backbone of mobile communication. They’re so integral to our lives that we rarely stop to think about what they actually are. But these tiny chips store a lot of important information that allows us to stay connected. This information is necessary for making calls, sending texts, or browsing the internet. Now you may be wondering exactly what information that is. This article will explain what kind of information you can find on SIM cards, why it’s so important, and what happens to that information when you swap the SIM out or discard it.
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Does the SIM card store data?
A SIM card, also known as a subscriber identity module, stores data — but it’s not just any data. It’s the vital information that keeps you connected to the world (network)! And no, your selfies and accidental lock-screen screenshots aren’t part of the package — they stay safely on your phone, not your SIM.
Here is a quick breakdown of what’s typically stored on your SIM card:
Carrier settings and subscription information. All SIM cards store details about the service provider, such as its name, cellular network settings, and subscription type (prepaid or postpaid). This information is necessary for your phone to stay connected and helps the mobile carrier manage your services and billing accurately.
Network-specific information. Your SIM stores data that helps your phone connect to the right network, including location details and network authorization data.
The ICCID (integrated circuit card identifier). This unique identifier is essentially the SIM card’s fingerprint. It helps the cellular network recognize your SIM card and establish a connection.
The IMSI (international mobile subscriber identity). This number is tied directly to you as a mobile user. It makes sure the network can authenticate your subscription and give you access to its services.
The Ki (encryption key). The Ki is a personal security key the mobile network uses to encrypt your communications, keeping them safe from prying eyes.
So while SIM cards don’t hold any personal data from the phone whatsoever (like photos, apps, or the operating system), they store the essentials — everything needed to keep you connected to the network. Without it, your phone simply wouldn’t be able to make phone calls, send messages, or access data.
What other information and data do SIM cards hold?
While they’re essential for mobile connectivity, SIM cards don’t act as additional phone storage. They don’t store your photos, apps, or other files. The data that they hold is limited to what’s necessary to keep your phone connected to the network. Why? Simply because the storage of a SIM is very limited. The standard SIM capacity ranges from 8 KB to 256 KB, which we can agree is not a lot. So, instead, all your personal files stay in your phone’s internal memory or the cloud.
That being said, it’s important to remember that SIM cards can “go bad” and stop working over time. If that happens, you might lose this data saved directly on the card. It’s always smart to back up your contacts just in case.
Are contacts stored on the SIM card?
SIM cards can store contacts, but the space is pretty limited compared to other options. As mentioned before, the size of SIM cards ranges between 8 KB and 256 KB, which holds about 250 contacts in total. These contacts are stored in a simple format, typically including only the names and phone numbers.
Back in the day, saving contacts to a SIM card was a handy way to transfer them between phones. You’d just pop the SIM into a new device, and your contact list would automatically transfer, too.
Because technology has come a long way since then, most people now prefer to store their phone numbers in cloud services like Google Contacts or iCloud. Cloud technology makes it easy to access contacts across multiple phones. Plus, if your SIM gets damaged or lost, you won’t lose your contacts.
If you still save contacts to your SIM, backing them up is a good idea. Modern smartphones offer much more storage and flexibility than a SIM card ever could, and they typically default to using cloud or internal storage anyway. This way, you’ll be sure all your contacts will be in one place.
Are text messages stored on the SIM card?
Some SIM cards can store text messages, but as mentioned earlier, the capacity is limited and varies depending on the card. This feature was more useful for older cell phones or users who preferred saving specific messages directly to the SIM.
Today, however, saving SMS to SIM cards is mostly irrelevant. In newer mobile devices, messages are typically saved to the phone’s internal memory or, in some cases, backed up to the cloud by default.
Are pictures stored on the SIM card?
SIM cards don’t store pictures. Their storage capacity is simply far too small to fit photo files. This very limited space is reserved for essentials like your phone number, contacts, and basic network data.
In the past, people might have thought of SIM cards as general storage, but today’s smartphones rely on internal memory, SD cards, or cloud storage for handling media files like photos and videos.
If you're switching SIM cards or upgrading your phone, make sure to back up your photos first. You can sync them to the cloud or transfer them to a computer or external storage to avoid losing them. Otherwise, you risk losing them during the transition.
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How to check information about your SIM on an iPhone and Android
While not all the information is easily visible, both iPhones and Android phones allow you to check essential details tied to your SIM, like your phone number and network info. If you’re curious to know more about your SIM card, you can find this information in just a few taps.
How to check information about your SIM on an iPhone
If you’re using an iPhone, here’s how to check what information is stored on your SIM card:
Open “Settings” on your iPhone.
Scroll down to find a tab called “General.”
Go to “About.” Here, you’ll find your SIM card’s ICCID and information about your network provider. If you tap “Network provider,” you’ll find your IMS status, which is the state of your device's connection to the network.
To find even more information about your SIM, return to the main screen of the “Settings” app. Scroll down and tap on “Cellular” (or “Mobile service” in some cases) > “SIMs.”
Choose your SIM card.
From there, you can explore additional details about your SIM, like your phone number and network selection, and adjust settings like data roaming or switch between 5G and 4G.
How to check information about your SIM on an Android
For Android users, checking information about your SIM card is just as easy:
Open the settings on your Android device.
Scroll down and tap on “About phone” > “Status.”
Tap on “SIM status.”
Here, you’ll see essential information like your network, roaming status, and phone number tied to your SIM card.
Will removing the SIM card delete everything?
The short answer is — it depends. Removing your SIM card won't delete everything on your device, but it can affect some data stored directly on the SIM card. For example, if you've saved contacts or certain text messages to the SIM only, those details will be lost once the card is removed. However, if you're using a newer device, this information is likely stored in the cloud or internal memory anyway, so you’ll be fine.
eSIMs (embedded SIMs) are the better digital alternative, offering the same functions but without the need for a physical card. The difference between an eSIM and a SIM is mainly in how they store and manage your carrier data. With an eSIM, your information is embedded in the device, making it more secure and less prone to damage. If you're worried about your physical SIM card getting damaged, an eSIM solves that problem and will not impact important data stored on your device.
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Aurelija loves traveling and snapping pictures, so having data abroad is as essential to her as having clean underwear. She believes everyone should be able to go online wherever they are and wants to help make that happen with her content.