What is an eSIM card? How is it helpful to you?

What is an eSIM card? How is it helpful to you?

If you used a cellphone in the last 30 years, you’ve undoubtedly encountered a SIM card. It’s a chip that tells your device which carrier, network, and phone number to use for cellular service. SIMs are now coming embedded inside smartphones in a reprogrammable microchip called eSIM – and Apple is going all-in by removing the physical SIM tray on the new iPhone 14 lineup. This new tech offers game-changing potential for the Internet-of-Things industry, plus powerful user experience improvements for the everyday wireless customer, so how can it work for you?

What is an eSIM?

eSIM stands for Embedded Subscriber Identity Module. Since 1991, SIM cards have been used to connect customers to their wireless carriers. The seventeen-digit code on the card identifies the country or region where the service works, the connected network, and a unique customer ID.

Diagram showing dimensions of eSIM, Mini SIM, Micro SIM, and Nano SIM

eSIM offers a new way to load carrier information onto your phone without using an external physical chip. Technically, an eSIM is a physical part – it’s a microchip embedded inside of your smartphone. This component can download carrier data remotely, enabling you to switch carriers on the spot.

If your phone has a physical SIM tray and an eSIM, you can actively use multiple lines at the same time. Some phones even support multiple active eSIM simultaneously. Toggling different carriers on and off can be accomplished easily with the press of a button in your phone’s settings.

That covers the basic functionality. Beyond the simple use of keeping connected to the wireless network, there’s huge potential for unique applications that will help streamline consumer and business connectivity practices.

Why eSIM?

We’re headed towards a more collectively connected society through the use of internet-enabled devices. Between wearables, automobiles, security systems, and industrial tech, the number of connected devices we’re buying is increasing every year – and we expect these devices to start working with minimal setup, right out of the box.

The “invisible” nature of eSIM creates a seamless experience for getting devices configured and connected. There’s no need to fumble around and try to organize small, plastic chips; activation is instant and doesn’t require any physical keys. Managing your lines or switching plans and carriers can be done remotely without any hassle.

Beyond convenience, the security boost over physical SIM is real.

For starters, eSIMs cannot be stolen without also stealing the device. This makes it much more difficult for thieves to use do port out scams, where they cancel a victim’s service and sign up for a new one using the stolen SIM.

In addition, eSIMs are immune to 2FA scams, in which a thief takes a physical SIM out of a phone and uses the associated phone number to get 2FA codes and log in to your private online accounts.

As a result, eSIMs provide a higher level of security than traditional SIM cards, making them an ideal choice for anyone who is looking to protect their personal data.

The impact grows massively as we consider the scalability of eSIM adoption across all connected devices.

Powerful use cases


  • Easily activate a free trial to test out a new carrier in an instant. No need to visit a retail store or wait several hours for a data transfer.
  • Switch between your business and personal phone number with a tap (or use both simultaneously).
  • Activate wireless service on all your products – be it a Tesla or a drone – without having to mess with multiple plastic SIM cards.
  • Travelers can remain connected around the world by activating a fairly priced eSIM plan from a local carrier in the country they’re visiting.


  • Account managers or IT personnel can remotely activate or adjust cellular plans on thousands of devices at once. 
  • Increase the longevity of connected machines and reduce maintenance costs by using eSIM to remotely update wireless plans at the end of a Telco contract.
  • Decrease costs and boost the efficiency of logistics operations by remotely managing tracker devices on global shipments and forgoing swapping out SIM cards.
  • Distribute devices with eSIM to automatically connect to the proper Telco upon the first bootup based on factors programmed during manufacturing.

Using an eSIM or a physical SIM?

Debating on how to activate your cellular service? Here’s a breakdown of the differences between using a physical SIM and an eSIM.

FeaturePhysical SIMeSIM
Locked to a carrier?One carrier per SIM.Reprogrammable to multiple carriers.
Dual-SIM (use two lines simultaneously)Some phones have two SIM card slots.Use an eSIM and a physical SIM, or 2 eSIMs simultaneously.
Switch phone lines on the flyPop out the SIM tray, remove the card, and pop a new one in.Go to phone settings and turn your lines on/off.
Size dimensions12.3mm x 8.8mm6mm x 5mm

Time-saving and ease of use are some of the most impactful considerations to make before choosing an activation method. Here’s what you should expect:

Activating a physical SIM plan

Illustration showing how physical SIM cards work
  1. Research and purchase a plan online or at a retail store
  2. Carrier gives you a SIM card with their network-specific information stored on it
  3. Insert the card in your phone
  4. The phone uses the data stored on the SIM card to connect to the network

Activating an eSIM plan

Illustration showing how eSIMs work
  1. Research and purchase a plan online
  2. Carrier shares a voucher with a QR code to instantly activate
  3. Instant activation by scanning QR code 
  4. The provisioning system sends a SIM profile to the eSIM embedded inside the phone and the service begins working

Simply put, activating with eSIM can save you an hours-long trip to the mall or waiting multiple days for delivery.

Once installed, the eSIM will function exactly like a traditional physical card – with one awesome bonus perk.

What is an eSIM card? How is it helpful to you?

eSIMs can store data from multiple carriers, so if you want to switch between multiple phone lines, you can access and toggle them all from your phone’s settings. So long as your phone is unlocked, you’ll be good to go with any phone plan you want.

How to activate eSIM on iPhone

It’s official! With the release of the iPhone 14, one major change is the lack of physical SIM card compatibility.

This means that customers will no longer be able to use a physical SIM card with their new iPhone. US Mobile has been preparing for this shift for some time now and has already built out a framework to ensure a smooth transition for customers. We’ve developed an eSIM solution that will allow customers to activate their service on their new iPhone in just 2 minutes.

Activating eSIM on US Mobile is quick, it’s friendly, and it’s never been easier to get cellular service.

See below to learn how you can activate your eSIM on Samsung and Pixel devices.

How to activate eSIM on Samsung

How to activate eSIM on Pixel

Using eSIM for International Roaming

Relax, you’re on vacation! We’ve engineered incredible solutions to reduce stress around keeping connected while abroad.

US Mobile International Data Dashboard

No more searching for the cheapest international data, trying (and failing) to understand what you’re signing up for at the merchant kiosk of a foreign airport, misplacing your American SIM, or returning home to surprise roaming charges! US Mobile will keep you connected with a few taps. 

Simply choose your destination & data allotment, and just like that – you’ll have service when you touch down at your destination. Manage your lines and track your balance with ease from the all-new US Mobile app.

The next iteration of SIM has arrived, and now that Apple has gone all in, other phone manufacturers are bound to follow suit. Already, the new Motorola razr and iPhone 14 lineup exclusively support eSIM, meaning you couldn’t use a physical card if you wanted to. Expect to see the widespread implementation of eSIM across phones, tablets, and everything in between in the coming years.

If you’d like to give eSIM activation a try, we’re offering you a free trial for unlimited domestic talk, text, & data – no commitments, no questions asked.

Will you be sporting eSIM on your next device? Or are you holding out on a physical SIM card for as long as possible?