A SIM card or SIM (Subscriber Identity Module) is a small chip that helps mobile devices connect to cellular networks. It stores key information that identifies you to your network provider and enables mobile services like calling, texting, and data access. While many people now use a global eSIM for international travel or to manage multiple mobile plans on a single device, physical SIM cards are still widely used worldwide. This guide explains what type of data is stored on a SIM card, how to access it, and how it differs from digital alternatives like eSIM.

What information is stored on a SIM card?

A SIM card stores only a specific set of data required for mobile network authentication and access. It does not contain photos, browser history, or application-related information. Instead, it holds identifiers such as IMSI (International Mobile Subscriber Identity), ICCID (SIM card serial number), and authentication keys. On older mobile devices, the SIM may also store a limited number of contacts or text messages.

What data is stored on a SIM card?

A SIM card stores specific technical information that allows a mobile device to connect and authenticate with a cellular network. The following table outlines the most common data types found on a SIM card:

Table: Common types of data stored on a SIM card.

Note: Most modern smartphones store contacts and messages on the device or in the cloud rather than on the SIM card.

How much data can a SIM card store?

SIM card storage capacity is very limited; it ranges from 8 KB to 256 KB, which is enough to hold only essential network-related information. This includes the subscriber’s identity, authentication credentials, and in some cases, a small number of contact entries or text messages on older devices.

What is stored in the SIM card on iPhone and Android?

While modern smartphones typically store personal data in internal storage or cloud services, there are still some differences between iPhone and Android devices when it comes to SIM card usage:

• iPhone: Apple devices do not store personal data; such as contacts, messages, or media, on the SIM card [1]. Instead, this information is saved in the phone’s internal memory or synced with iCloud. If the SIM was previously used in another device, you can import existing contacts, but no new user data is stored on the SIM [2].

• Android: Most current Android devices also avoid storing personal data on the SIM card. However, some older models may still read contacts or text messages saved directly on the SIM. This is due to how legacy Android systems handled data management.

How to see and check what is stored on a SIM card?

You can view or check SIM card data through your phone’s system settings. The exact steps vary depending on whether you use an iPhone or an Android device:

On iPhone

1. Open Settings > Contacts > Import SIM Contacts.

2. Choose where to save the imported contacts, such as iCloud or local device storage.

3. Wait for the import process to finish.

4. Open the Contacts app to confirm that the contacts have been added.

 On Android

1. Go to Settings > Connections > SIM card manager.

2. Tap the SIM slot in use (e.g., SIM 1) to view available actions.

3. Select View SIM Contacts or SIM Messages, depending on your device.

4. If supported, transfer the data to internal storage or sync it with your preferred account.

Disclaimer: The exact steps and menu names may vary depending on your device model, manufacturer interface, or operating system version. For accurate and reliable guidance, please consult your device manufacturer’s official support resources.

Roamless eSIM: An Ideal Alternative to SIM Cards for International Travel

An eSIM is a digital alternative to traditional SIM cards that allows you to activate mobile service without inserting any physical chip into your phone. Here are several advantages of using Roamless eSIM over physical SIM cards:

• Online activation: You can activate a data plan instantly through the Roamless app without needing to insert or replace a SIM card.

• Multi-country coverage: Roamless offers mobile data access in over 200 destinations, eliminating the need for local SIMs in each country.

• No physical handling: There is no risk of losing or damaging a SIM card since everything is managed digitally on your device.

• International calling: Roamless supports in-app voice calls starting from $0.01 per minute, without requiring a separate calling plan.

• Device flexibility: You can move your eSIM between compatible devices without ordering a new SIM or visiting a store.

For more information, you can check out our posts on What is eSIM, eSIM vs Physical SIM and How to Convert Physical SIM to eSIM. 

Frequently Asked Questions

Does a SIM card store data?

- Yes, but only limited types of data. A SIM card stores essential network information such as your subscriber identity (IMSI), SIM serial number (ICCID), and authentication keys. Some older SIM cards may also hold a small number of contacts or text messages.

Do SIM cards store photos?

- No. SIM cards do not have the capacity to store photos or other media files. Images and videos are saved in your phone’s internal memory, an SD card, or a cloud account.

Does a SIM card store contacts?

- Yes, but only in specific cases. SIM cards used in older or basic phones can store a limited number of contacts, typically just names and phone numbers. On newer smartphones, contact information is usually stored in the device memory or synced to a cloud service.

Does a SIM card store text messages?

- Sometimes. Some SIM cards can store a limited number of SMS messages, especially when used in older mobile phones. However, most modern devices save messages directly to the phone’s internal memory or in the messaging app, not on the SIM card.

Is your phone number stored on SIM cards?

- Not exactly. Your phone number is associated with the SIM card by your mobile carrier, but it is not always physically stored on the card itself. Instead, the number is linked through the carrier’s network configuration and can be read by the device as part of the SIM profile.

Is browser history stored on SIM cards?

- No. SIM cards do not store browser history, cookies, or any internet activity. This kind of data is managed by your phone’s operating system and stored in the browser app or internal memory.

Can I check what is stored on a SIM card?

- Yes. You can check SIM-stored data such as contacts or text messages using your phone’s settings. On Android devices, go to Settings > SIM card manager to view contacts or messages if supported. On iPhones, use Settings > Contacts > Import SIM Contacts to import and view any saved contact entries.

Does an eSIM offer better security than a physical SIM card?

- Yes. eSIMs offer a security advantage because they cannot be removed from the device without stealing the phone. Physical SIM cards, on the other hand, can be taken out and exploited in SIM swap scams [3].

Sources

[1] Apple Support Community. ‘’What data can be retrieved from a SIM card?’’, September 2024. - https://discussions.apple.com/thread/255746591?sortBy=rank

[2] Apple Support. ‘’Import contacts from your SIM card to your iPhone’’, May 2025. - https://support.apple.com/en-us/109325

[3] Federal Communications Commission. ‘’eSIM Cards FAQ’’, Accessed July 2025. - https://www.fcc.gov/sites/default/files/esim_cards_faq.pdf