What Is an eSIM? A Comprehensive Beginner’s Guide

The first SIM card was launched in 1991 and was about the size of a credit card. Since then, SIM cards have continued to shrink, and today’s version, known as eSIM, completely eliminates the need for a physical card inside your device.

So, what is an eSIM really, and how does it work? In this guide, we’ll explain everything you should know about eSIMs, from their underlying technology to key advantages and drawbacks. We’ll also discuss what to focus on when choosing an eSIM to ensure you get the best coverage and security.

What Is an eSIM Card?

An embedded SIM (eSIM) is a digital version of a traditional SIM card that enables your device to connect to a mobile network without needing a removable, physical SIM. The eSIM chip is permanently built into the device or “embedded,” and you can activate service by downloading a mobile plan. Unlike physical SIM cards, eSIMs can store multiple profiles, making it easy to switch carriers or plans without needing to swap cards.

How does an eSIM work?

An eSIM works exactly the same way as a traditional SIM; it authenticates your device with your mobile carrier so you can complete the following activities:

• Connect to the network
• Send and receive text messages
• Make and receive phone calls
• Use cellular data

The main difference is that activation occurs digitally. Instead of inserting a card, you download an eSIM profile using a QR code, carrier app, or automatic or remote SIM provisioning (RSP).

What Are the Advantages of an eSIM?

The most obvious advantage of an eSIM card is convenience since you don’t have to purchase a new SIM card or go to your carrier to activate a plan. Since the chip is embedded into your phone, all you need to do is activate your eSIM remotely (which can be as simple as scanning a QR code), and you’ll be ready to connect to a mobile network anywhere.

In addition to convenience, eSIMs offer a range of advantages, including:

1. Enhanced security
2. Multiple profile support
3. Affordability
4. Reduced environmental waste

1. Enhanced Security

Physical SIM cards can get physically damaged or lost when you’re transferring them from one device to another. This isn’t an issue with an eSIM as it doesn’t involve a physical card. Since they are less prone to damage, eSIMs are more durable.

If your device is stolen, thieves can’t remove the eSIM to disable tracking, unlike with physical SIMs. Disabling an eSIM usually requires the carrier’s assistance and authorization, so malicious actors or thieves can’t tamper with it.

Compared to physical SIM cards, eSIMs are less vulnerable to attacks and hacks, such as SIM cloning. eSIMs are typically protected with encryption, and since they’re embedded into devices, they can’t be easily duplicated.

2. Multiple Profile Support

A physical SIM card stores one carrier profile; if you frequently travel to Europe or any place abroad, want to switch carriers, or have a work phone number, you’ll need to do one of the following:

1. Constantly swap your physical SIM cards
2. Use a device with dual SIM support

An eSIM can hold multiple carrier profiles for maximum convenience; depending on your device, you can typically store between five and eight eSIM profiles. Simply toggle between different profiles according to your schedule and needs to maximize the potential of eSIM. With just a few clicks, you can easily switch between carriers and plans to always get maximum affordability, flexibility, and coverage, regardless of your location.

3. Affordability

In the past, when traveling internationally, you either had to purchase a local SIM or pay high roaming fees to ensure a stable and consistent network connection. eSIMs change this; you can set up a local eSIM on your device and connect to a network without paying expensive fees or buying a physical SIM that you’ll only use for a few days.

4. Reduced Environmental Waste

eSIMs support a more sustainable approach to technology. Unlike physical SIM cards, which are made of plastic and contribute to environmental waste, eSIMs are embedded into devices, occupying less physical space. They also don’t require separate packaging and shipping, which reduces their environmental footprint.

What Are the Drawbacks of eSIMs?

While eSIMs offer numerous advantages, they also have some drawbacks you should consider, including:

How To Set Up an eSIM: iPhone and Android Set Up Processes Explained

The first step you’ll need to complete, regardless of your device, is to check whether your phone supports eSIMs. You can perform a Google search or access your device’s settings to check if adding an eSIM is an available option. Once you confirm compatibility, you’ll need to purchase an eSIM plan with the chosen provider. Visit the carrier’s website and select a plan that suits your needs.

After the payment is completed, you’ll likely receive a QR code, which you need to scan to add the eSIM to your device. This process varies depending on whether you have an iPhone or an Android device.

Setting up an eSIM on an iPhone

Here’s how to activate an eSIM on your iPhone:

1. Scan the QR code you’ve received from your carrier
2. You’ll receive the Cellular Plan Detected notification; follow the link
3. Tap Continue at the bottom of the screen
4. Select Add Cellular Plan. You may be required to enter a confirmation code; use the number provided by your carrier

If you have an iPhone with iOS 17.4 or later and receive the QR code via email or in a browser, you can simply tap the code and select Add eSIM.

Setting up an eSIM on an Android Device

Follow the steps below to set up an eSIM on your Android:

1. Open Settings and go to Connections
2. Tap SIM manager
3. Choose Add eSIM and scan the provided QR code. In the same settings, you can also transfer a SIM from another phone or search for available eSIMs
4. Follow the on-screen prompts to complete the activation

eSIM FAQs:

Below, you’ll find answers to some of the most frequently asked questions regarding eSIMs:

Does an eSIM Give You a Phone Number?

It depends on the provider and your preferences. Some eSIMs offer only mobile data, without a phone number. That can be convenient if you’re traveling abroad and only want the internet connection.

Obtaining an eSIM with a phone number is more practical for everyday use. You can enjoy the convenience and flexibility of eSIMs and eliminate the need for physical SIMs altogether if that’s your goal. Some providers enable you to choose whether to get a new phone number with your eSIM or transfer your existing one for maximum convenience.

Does an eSIM Drain Phone Battery?

A single eSIM doesn’t affect power consumption any more than a physical SIM card does. If you use both an eSIM and a physical SIM or multiple eSIMs simultaneously, you may notice increased battery consumption because the device needs to maintain these connections.

Factors that affect your battery performance include:

• Background apps
• Screen brightness
• Location services
• Outdated software
• Poor signal strength
• Processor strain

Do All eSIMs Offer the Same Level of Security?

All eSIMs, regardless of the carrier, share certain characteristics, including being less prone to physical damage and theft due to their embedded design. In this sense, eSIMs provide the same degree of security, but there’s another aspect to consider: network-level threats.

The security of an eSIM is determined by the carrier that offers it. If a carrier has poor security protocols, it may be vulnerable to data breaches and cyberattacks, which could impact your eSIM and compromise your personal information.

A carrier’s security largely depends on its:

• Infrastructure: Many traditional carriers still use legacy systems that can expose user identifiers and activity data, which could be intercepted by malicious actors.
• Authentication systems: Mobile carriers with poor authentication protocols can’t properly protect you from attackers attempting to access your eSIM, enhancing the risk of unauthorized activation and account takeover.
• Data handling policies: Carriers that collect and store a significant amount of your personal information without robust security protocols directly jeopardize your privacy and security.

The level of security you’ll get with an eSIM depends on who manages it, and that is why you should carefully choose your carrier.

A privacy-first eSIM provider like Cape combines eSIM technology with high-grade security. With our own infrastructure, minimal data collection, and advanced SIM profile management, we provide reliable coverage while protecting your information and identity from network threats.

Cape Makes Security the Standard: Here’s How

Cape is America’s privacy-first mobile carrier, providing premium, unlimited, and nationwide call, text, and data. Unlike other providers, our service is built from the ground up with privacy and security at its core.

Mainstream carriers track you and store your data, often without your consent. Cape takes a different path—we collect the absolute minimum amount of information to provide you with service.

Any information we do collect is retained for the minimum amount of time possible. Most carriers store call data records (CDRs) for years, sometimes indefinitely. Cape stores yours for just 24 hours, and we have a commitment to never sell your data.

Cape service includes security features that no other carrier offers:

• Minimal Data Collection: During onboarding, we don’t ask for your name, Social Security number, or address. We only collect what’s necessary to provide you with service, and we retain it for the minimum amount of time possible.
• Identifier Rotation: Every SIM card has an International Mobile Subscriber ID (IMSI), a unique identifier which your device uses to register with cellular networks. Most carriers assign a fixed IMSI that stays the same for the life of your account, making it easy for your carrier, advertisers, and bad actors to identify and track your device over time. Cape breaks that pattern by allowing subscribers to automatically rotate their IMSI every 24 hours, so you appear as a different subscriber every day, making it much more difficult for anyone to follow or track your movements.
• Secondary Numbers: Your phone number is a target for data brokers and scammers. Retailers, websites, apps—everyone is routinely asking you to share your number with them, which exposes you to a variety of risks. Many turn to VoIP numbers to use as secondary lines, which can be helpful, but cost extra, don’t work with 2FA, and aren’t encrypted. Cape provides subscribers with two free additional SMS/MMS lines that are middle-to-end encrypted. With secondary numbers, you can reserve your primary number for communicating with your close friends and family, and use the other for anything from shopping and signing up for discounts, to receiving secure OTPs.
• Disappearing Call Logs: Call and text records reveal a lot about you, from who your closest relationships are to when and where communication took place. With traditional carriers, your call and text metadata doesn’t just disappear; it’s retained, analyzed, and folded into a lasting customer profile. At Cape, we’re built to forget and delete these records after just one day.
• Last Mile Encrypted Texting: SMS messages are unencrypted, yet many of us still use it to receive One-Time Passwords (OTPs) for our most sensitive accounts, leaving them vulnerable to a variety of threats. Cape allows subscribers to encrypt and route all SMS/MMS messages through the Cape app. When enabled, SMS/MMS messages sent to Cape subscribers will be middle-to-end encrypted and decrypted securely within the Cape app. This protects any messages that may be intercepted from being read. This feature is only available on iPhone; Android coming soon.
• SIM Swap Protection: A SIM swap happens when an attacker convinces your carrier to transfer your number to their device, allowing them to receive your calls and texts, trigger password resets, and gain access to your accounts. Cape protects against SIM swaps by removing humans entirely from the loop. During sign-up, you receive a 24-word phrase that generates a private key tied to your number. This phrase is the only way to move your number to a new device or carrier. No one, not even Cape, can transfer your number without your phrase, giving you full control over your number.
• Network Lock: Traditional cellular networks were designed for interoperability, not security. Outdated and legacy network protocols like SS7 have vulnerabilities that allow attackers to hack in and track your location, intercept your calls and texts, and steal sensitive information. Cape’s Network Lock uses a proprietary signaling proxy to verify that your device’s physical location matches the network it’s trying to attach to. If anything looks suspicious, like a mismatched location, we block the connection.
• Encrypted Voicemail: Voicemails can reveal more than you think, from personal messages to authentication codes, yet most voicemail systems are outdated and unencrypted. Cape encrypts your voicemails so that only you can access them.
• Secure Global Roaming: While you’re traveling abroad, your phone connects to local telecom providers to provide you with connectivity. But not all networks are secure, and not all governments treat privacy the same. Cape routes your traffic through our U.S.-based mobile core. Our Secure Global Roaming gives you the convenience of international data roaming without exposing your identity or communications. You get up to 15GB per month of international roaming included in your plan.

These features are made possible because we’re a “Heavy” Mobile Virtual Network Operator (MVNO).

Other MVNOs (such as Mint Mobile, Cricket, etc.) simply ride on top of the mobile core, SIMs, and physical infrastructure of their underlying MNO partner. At Cape, we actually own our own mobile core and provision our own SIMs.

This gives us control over how accounts are authenticated, what data we do and don’t collect, how long we retain it for, as well as the ability to build proprietary features like Identifier Rotation. No other carrier on the market has this capability.

Reclaim Your Privacy: Switch to Cape Today

Ready to ditch traditional telcos and switch to a privacy-first mobile carrier? Visit cape.co/get-cape to sign up.

Try Cape completely risk-free for just $30 for your first month. No contracts, no personal or credit card info needed, no hidden fees or taxes, and no strings attached.

Thanks to our partnership with Proton, you can also take your privacy a step further and get Proton Unlimited or Proton VPN Plus for only $1 for the first six months.