What data is stored on my SIM card?


What Data does a SIM Card hold?

A SIM card or ‘Subscriber Identity Module’ card is the small chip that is required for most types of phones to access data and make calls. They allow your chosen mobile network to identify you, by storing your International Mobile Subscriber Identity number (IMSI) and your Mobile Subscriber Integrated Services Digital Network number (MSISDN). In other words, they store the data that tells your local mobile tower your mobile number and what types of connections you can make.

But SIM cards don’t contain just that information. A standard SIM card holds less than 1 MB of data. That doesn’t sound like much, but that’s enough space for 250 contacts.

Why does the data your SIM contains matter?

Knowing what your SIM can hold is useful for two reasons. Storing contact data on your SIM is one way of transferring that data if you were to get a new phone. SIMs can also store text messages and recent network information, such as which local networks that you were last connected to, which can be used to work out your approximate location.

Is a SIM card the best place to store my data?

While historically SIM cards were great for moving data between phones, the shift towards data rich contacts – contacts where you store their emails, addresses, and even photographs – plus the development of cloud technology, have made them less relevant.

Although SIMs can hold up to 256KB of data, phone hardware and cloud memory have far outstripped this, with modern smartphones having access to hundreds of gigabytes of storage, millions more than a standard SIM.

Where should I store my contact data?

Storing contacts on a SIM is still perfectly valid, and will function just as well in most situations. However we’d recommend you consider storing your contacts in the cloud. This will allow you to store far more data, and a great number of contacts. It is also more secure, as if you lose your phone, or it is stolen, all your contact details won’t be lost.

Related articles: