How Do eSIM Cards Work?

SIM cards are the small devices within your cell phone that connect your phone number to your carrier, giving your phone permission to send texts, calls and use data on the mobile network. These cards have recently turned digital. Physical SIM cards (usually Nano SIMs in current phones) take up way more space than their eSIM counterpart. Cell phones are optimizing space, and bulky physical SIM cards are making way for smaller, embedded hardware. Let’s talk about eSIM cards, how they work, and what people say about the eSIM takeover. 

What is an eSIM Card? 

First things first: eSIM cards do the same things physical SIM cards do. They connect your device to your carrier’s mobile network and keep your number and other account information. The card has decreased in size through the years, and going from physical SIM to eSIM is a logical continuation of this process. The embedded SIM is a chip that’s a part of your phone’s hardware rather than a piece that’s inserted into a port in your phone. 

Most phones on the market are compatible with physical SIM cards and eSIM cards. Which one currently connects your phone to the network? They will both provide the same connection speed and coverage. Using an eSIM card is nice, but physical SIM cards work just as well now. The big advantage eSIM provides is the ability to hold multiple accounts and reprogram itself with instructions from new carriers. For instance, if you have an eSIM phone plan with Carrier #1 and want to switch to Carrier #2, the new carrier will send online instructions (often a QR code) that instantly switch over your account to the new carrier. No more waiting for a chip to arrive in the mail!

eSIM creation and production were originally driven by the creation of the Internet of Things, the web of connected smart devices that blankets many cities, homes, and urban areas. The physical SIM card and its removable housing take up a lot more space than an eSIM card. This new technology created many options for new, smaller devices. Through their small profile, eSIMs fit into just about any electronic device, allowing networks to grow with devices that can connect to the internet and send/receive instructions. Companies can create a citywide smart device network and send instructions remotely. 

Soon after, cell phone manufacturers grew interested in eSIMs using that technology in their new devices. Although cell phone manufacturers have added eSIM compatibility to many of their devices, US carriers have dragged their feet throughout the whole process.

eSIM Adaptation by US Carriers

US cell phone carriers were not keen on eSIM adaptation when they were first made available in cell phones. eSIMs make it easier for users to switch carriers, and cell phone companies do not want that. Switching carriers with eSIM can happen within the hour, as the new carrier receives your information and sends you an activation code through email. 

Their general dislike of eSIMs in cell phones has waned as their popularity increases. Just about every US carrier now provides eSIM cell phone plans along with physical SIM cell phone plans. It is great for customers because they can choose which kind of SIM card is best. The SIM card does not affect your data speeds or call quality. While US carriers support the development of eSIM, they were pushed there by its widespread adoption into smartphones and other devices. Apple’s iPhone series 14 is shipped in the United States without any physical SIM slot, making it one of the first eSIM-only phones out there. Assuming that other manufacturers follow suit, there will be a gradual decline in physical SIM usage over the next few years as more and more eSIM-only phones are put on the market. 

How do eSIM Cards Work? 

Your eSIM card functions in the background, holding all your device’s information inside and keeping your account settings connected to your mobile network provider. These cards connect your device to mobile networks. Since the beginning, SIM cards have done just that. While cell phones have increased in power and complexity, it follows that SIM cards can do the same task while taking up way less space. SIM cards, over the few decades since their first usage, have gotten smaller and smaller. 

The Standard SIM Card

Let’s quickly backstep through time to the age when phones were much larger, stationary devices. People were issued, in essence, a credit card with SIM information that contained their billing information. Whenever they got to a phone, they would slot it in and could use the phone to make calls. This was a nice way to utilize phones, as you could move any number of phones a day and pay for each of them on the same account rather than carrying around enough change for payphone use. 

As phones increased in portability and decreased in size, there was a need for smaller SIM cards. The actual SIM portion only took up part of the card, so it was easy to design a smaller model to fit into a phone and stay there. Thus, the Mini SIM came to be. This much smaller card saved on space and became semi-permanent in devices. If they so chose, people could still swap out their SIM cards, but people are changing devices with much less frequency, and swapping devices with eSIM, while a little more work, is still very easy. 

Other eSIM Applications

Alongside smartphones, eSIM cards are utilized to power devices on the Internet of Things and in various industry and manufacturing capacities. 

• eSIM cards connect small devices to the Internet of Things. Integrating eSIMs into smart devices instead of physical SIMs opened many doors for product designers to find better models for their electronic devices. 
• eSIMs are used in industry and manufacturing to connect devices in bulk to a single network. With the remote programmability of eSIM devices, it is now much easier to change service providers. All devices can switch at once rather than waiting on the bulk shipment of physical SIMs.

When to Use eSIM Cards

Right now, the main draw for eSIM mobile plans is when you want two numbers on one device. Well, the main draw is if it’s something you want. Converting to an eSIM cell phone plan will not change much within your device, but it is cool. It also allows your cell phone to store multiple accounts and keep two active simultaneously. 

Dual-SIM Devices

Anyone who uses multiple numbers can use eSIM cards to condense both numbers into their primary device. When you have multiple SIM cards on the same phone, you can switch between them at will. With a phone like this, you have an additional setting, normally in your drop-down menu, that lets you switch what the active SIM card is on your phone. While only one SIM card is active at a time in your user interface, you will receive notifications from both numbers simultaneously. 

If you want to set up a phone like this, you will put in which cell phone number you want active for a number of common circumstances. For instance, your phone will default to a number when you call and text non-contacts, but you can split your contacts into groups and set which number is used with each group. You can also choose which SIM card is in charge of your data usage and switch between them as you wish. Anyone with an unlocked phone can create a dual-SIM device, but only some need to. Here are a pair of common cases for dual SIM device activation. 

Business Phones

There is nothing new about a phone just for business, but with an eSIM phone, you can keep your business number on your personal device. Since it is a separate number and separate account, you have more freedom to customize the notification settings than you would be working with only one number. You can, for instance, set your work number to do not disturb during non-work hours or when you are on vacation. This lets you keep the work-life separation without having a second device. 

This is also a great way to purchase new plans if you travel internationally.  

International SIM Cards

A lot of people travel internationally with some regularity, and a dual SIM active phone lets you evade roaming charges and lower data speeds while abroad. Many United States companies have international roaming agreements, but those agreements can quickly add up in price if you spend a lot of time internationally. You can purchase local plans in your international destinations with an eSIM device and take advantage of the lower prices than US companies. 

Unlocking Your Device

You can only take advantage of a dual-SIM device if your cell phone is unlocked. Locked phones do not allow you to change carriers, a rule imposed to discourage people from taking advantage of device deals. A major wireless carrier may give a new smartphone at a much-discounted rate to a new customer with a trade-in. Because that phone is locked, the customer can’t leave the company immediately, taking that new phone elsewhere. 

While the exact requirements to unlock your phone differ from carrier to carrier, they follow the same general criteria, which are as follows: 

• Your phone must be paid off
• A set amount of time has passed
• You must have purchased it from the carrier
• It is not claimed as lost or stolen
• Your account is in good standing

Some carriers, like Verizon, will unlock your phone immediately after you meet their criteria, while others, like AT&T, require a device unlock request submission. To check if your phone is unlocked, go into your settings and, if you have an iPhone, go to cellular and cellular data. If you see “Cellular Data Options,'' your phone is unlocked. For Android phones, go to settings and mobile networks. If you see network operators, then your phone is unlocked. If your device doesn’t meet the above criteria, you cannot add a cell phone plan from a new carrier. It is in your best interests to unlock your phone as soon as possible to take advantage of a dual-SIM device if you need it. 

One number is enough for the majority of people. However, we still recommend unlocking your device because once it is unlocked, you can change carriers and bring it with you. Lots of cell phone companies rope in customers with device deals that are a two or three-year contract, which will keep your phone locked to the carrier and, by extension, you locked to the carrier. There are a lot of excellent cell phone plans given by major wireless carriers and MVNOs for you to explore looking for the best cell phone plan. 

Key Takeaways

Figuring out how eSIM cards work is a great step to understanding whether physical SIM or eSIM is right for you. We hope that you consider yourself a master on this topic, but we want to leave you with some key takeaways to refresh your memory with the most important information in this article. 

• Almost every major US carrier supports eSIM phone plans.
• Both eSIM cards and SIM cards do the same tasks within your device.
• There are a lot of applications for eSIM cards outside of smartphones and cell phone plans, and that is where the bulk of them are operating.
• The significantly smaller profile of the eSIM card lets smart devices operate more efficiently on the Internet of Things. 
• eSIM cards provide the most benefit to users with multiple cell phone numbers. 
• Businessmen and travelers are some of the most common users of dual-SIM phones, as they can keep both numbers on a single device. 
• Utilizing eSIM phones lets companies make instant changes to all of their devices. 

Frequently Asked Questions

There are a lot of questions surrounding embedded SIM cards, from their usage in the personal smartphone industry, and their development within the United States. This section will answer some of the most asked questions regarding how eSIM cards work. 

How does an eSIM actually work?

Embedded SIMs allow you to activate a mobile phone plan from your service provider. This also allows cell phones to utilize multiple active numbers.

What are the disadvantages of eSIM?

The main disadvantage of using eSIM is that it is harder to switch devices. They do make it easier to switch carriers, and allow phones to have multiple active accounts.

How do I use eSIM instead of a SIM card?

All carriers that support eSIM cell phone plans have procedures in place to activate an eSIM card on a new device, with a new account, and let you transfer your current SIM card into an eSIM card if you want. 

Which Phones Support eSIM? 

Phone manufacturers have added eSIM compatibility with the majority of their recent devices. It is easy to check which phones have eSIM compatibility--from there, you can find the best phone for you. 

What Does eSIM Let You Do? 

eSIM cards allow quicker and easier changes to your wireless carrier because they can be reprogrammed. Physical SIMs require the shipment of a new card from your carrier, while eSIMs allow carriers to send an email with all the relevant information.  This is a significant boon for the manufacturing industry and other areas that operate large numbers of IoT devices, making software or carrier change much more efficient. 

Which US Carriers Support eSIM? 

While all three major US carriers support eSIM, they are not interested in the new technology. The ease of using physical SIM cards for individual and family plans works very well, giving major carriers fewer incentives to switch to eSIM-only plans. 

Which Tablets and Laptops Support eSIM? 

All the iPads support eSIM and open up the opportunity for you to connect those devices to a mobile network with ease. There are limited laptops with eSIM compatibility, but the new Dell Latitude line is a good place to start. 

How Do You Activate an eSIM Phone Plan? 

There are two common ways to program the eSIM card and activate your eSIM phone plan. The simplest way is to sign up for a plan through an app on your phone or use that app to log in to your account and activate it that way. 

The other way is to generate a QR code from the carrier’s website and scan it with your cell phone. While a little more time-consuming, this is the most supported way to activate an eSIM phone plan on your device. 

Are eSIM and 5G Related?

Nope! They are two new standards that developed simultaneously, and while there is no specific tie, they do influence one another. With the advent of 5G, networks became much more robust and could support a lot more devices in a given area. This has fueled more research and development into the Internet of Things and other tiny devices with an Internet connection.