We are independent & ad-supported. We may earn a commission for purchases made through our links.

Advertiser Disclosure

Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.

How We Make Money

We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently from our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

What Is a Subscriber Identity Module?

By T.S. Adams
Updated May 16, 2024
Our promise to you
EasyTechJunkie is dedicated to creating trustworthy, high-quality content that always prioritizes transparency, integrity, and inclusivity above all else. Our ensure that our content creation and review process includes rigorous fact-checking, evidence-based, and continual updates to ensure accuracy and reliability.

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

Editorial Standards

At EasyTechJunkie, we are committed to creating content that you can trust. Our editorial process is designed to ensure that every piece of content we publish is accurate, reliable, and informative.

Our team of experienced writers and editors follows a strict set of guidelines to ensure the highest quality content. We conduct thorough research, fact-check all information, and rely on credible sources to back up our claims. Our content is reviewed by subject matter experts to ensure accuracy and clarity.

We believe in transparency and maintain editorial independence from our advertisers. Our team does not receive direct compensation from advertisers, allowing us to create unbiased content that prioritizes your interests.

A subscriber identity module, otherwise known as a SIM, is a circuit which stores networking information and subscriber information for a mobile device, such as a cell phone or computer. The subscriber identity module acts to uniquely identify an individual on the specific network, validating their right to use the network along with other specific information such as passwords and services to which the user has subscribed. Without a working subscriber identity module, the network capabilities of the associated device are thereby crippled.

Think of a subscriber identity module as ticket allowing the end-user to see a movie or show. It provides them with access to the theater, the mobile network to which they are connecting. It does this by storing Integrated Circuit Card Identifiers (ICCID) numbers. Integrated Circuit Card Identifiers numbers are comprised by a combination of the identifier for the network carrier — such as the specific cell phone company — the country code for the end-user's region, the end-user's individual account number, and a check digit. A check digit is a validation number, much like the security code on the back of a credit card.

In addition to this, a SIM also contains an authentication key for the specific mobile network the end-user is connecting with. This is a bit like a wireless security code for wireless networks, ensuring that not just anyone can hop on and steal bandwidth from the network. Using a combination of codes, such as an ICCID code and an authentication code, ensures that SIM cards are not easily hacked.

Subscriber identity module cards come in three main sizes. The first size is roughly the same dimensions as a credit card; but as mobile devices continued to shrink in size, this form factor was largely abandoned. Today, the most common types of SIM cards are Mini and Micro SIMs. Mini SIMs are just 25 millimeters (just under one inch) by 15 millimeters (roughly 0.6 inches) in size. Micro SIMs are only 15 millimeters (0.6 inches) by 12 millimeters (roughly half an inch), making them useful for the smallest types of mobile electronic devices.

EasyTechJunkie is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.

Discussion Comments

EasyTechJunkie, in your inbox

Our latest articles, guides, and more, delivered daily.

EasyTechJunkie, in your inbox

Our latest articles, guides, and more, delivered daily.