What Is an eSIM and How Do You Set One Up?

If you bought a new iPhone in the US in the last few years, you may have noticed something missing: the little SIM tray. Google’s newest US Pixel phones have gone the same way. That leaves a lot of people asking the same question at the carrier counter or on a hotel Wi-Fi network abroad: what exactly is an eSIM, and how do I get my phone number onto it?

The short version: an eSIM does the same job as a SIM card, but it’s software instead of plastic. This guide explains how it works, where it helps (travel and switching carriers are the big ones), and the exact setup steps on iPhone and Android.

What an eSIM actually is

A SIM, or subscriber identity module, is what tells a mobile network that your phone belongs to a paying customer. For decades that meant a small chip on a removable card. An eSIM, or embedded SIM, is a secure chip soldered inside the phone that can download and store carrier “profiles” over the air.

The industry standard behind this comes from the GSMA, the global mobile operators’ association. Its SGP.22 specification defines remote SIM provisioning for consumer devices such as phones, tablets and watches. In plain terms, it’s the rulebook that lets your phone safely download a carrier profile from a QR code or app, and lets carriers and phone makers work together.

Apple describes eSIM as a digital SIM that lets you activate a cellular plan from your carrier without a physical SIM. Apple also says an iPhone can hold up to 8 or more eSIMs, though you’ll typically use 1 or 2 at a time.

If you want a refresher on other device and network terms, the tech glossary covers the basics.

eSIM vs physical SIM at a glance

Why eSIMs are useful

Switching carriers is faster

With a physical SIM, changing providers often meant waiting for a card in the mail. With an eSIM, many carriers can activate service the same day through their app or a QR code. Apple points out that you don’t have to obtain, carry or swap physical SIM cards.

Travel gets easier

This is where most people fall for eSIMs. You can keep your US line active for texts and calls while adding a separate data plan for the country you’re visiting. Apple’s travel guidance describes 2 routes: use your carrier’s international roaming, or buy a travel eSIM from a local or worldwide provider. Many travelers install the travel eSIM at home, then switch it on when the plane lands.

For a full breakdown of day passes, travel eSIMs and Wi-Fi Calling, see our guide on how to use your phone abroad.

Dual SIM without a second phone

Most modern phones support 2 lines at once. Apple says iPhone 13 models and later support Dual SIM with 2 active eSIMs. Google says Pixel 7 and later can run 2 eSIM profiles if your carrier allows it. That’s handy for a work line and a personal line on one device.

A little extra security

Apple says eSIM is more secure than a physical SIM because it can’t be removed if your phone is lost or stolen. A thief can’t simply pop out your card and put it in another phone to receive your text-message codes. That doesn’t replace good account security, so it’s still worth setting up two-factor authentication with an app or passkey where you can.

Key takeaway: An eSIM doesn’t change your plan, price or phone number. It only changes how the plan gets onto your phone, which makes switching, traveling and running 2 lines much simpler.

Does your phone support eSIM?

Most phones sold in the last several years do. Here’s how to check:

• iPhone: Apple says you need an iPhone XS, XS Max, XR or later. iPhone 14 and later models sold in the US have no SIM tray at all, so they are eSIM-only.
• Google Pixel: Google says Pixel 3a and later support one physical SIM plus one eSIM, and Pixel 10 models sold in the US (except the Pixel 10 Pro Fold) are eSIM-only.
• Samsung and other Android phones: Many recent flagship models support eSIM, but some budget models don’t. Check your model’s spec page or look for an “Add eSIM” option under your SIM or connection settings.

Locked vs unlocked phones

If you plan to use a different carrier, including a travel eSIM provider, your phone usually needs to be unlocked. Apple notes that to use 2 different carriers, your carrier must unlock your iPhone. The FCC advises that, unless a phone was sold as unlocked, you should assume it’s locked to the carrier that sold it and ask that carrier about its unlocking policy.

On iPhone, go to Settings > General > About and look for “No SIM restrictions” next to Carrier Lock.

How to set up an eSIM on iPhone

Apple lists several ways to activate an eSIM. Which one you use depends on your carrier.

1. eSIM Quick Transfer from your old iPhone. Both phones need to be signed in to the same Apple Account, near each other with Bluetooth on, and running iOS 18.4 or later. During setup, follow the prompts to transfer your number. After setup, go to Settings > Cellular > Set Up Cellular (or Add eSIM) and choose Transfer From Nearby iPhone. Your old SIM stops working when the new one activates.
2. Carrier activation. If you bought the phone from your carrier, the eSIM may already be assigned. It activates during setup. If you add it later, tap the “Carrier Cellular Plan Ready to Be Installed” notification.
3. QR code. Your carrier or travel eSIM provider sends a QR code. Open the Camera app, scan it and tap Cellular Plan Detected. On iOS 17.4 or later, you can also tap and hold a QR code in an email or web page and choose Add eSIM.
4. Carrier link or app. Some carriers send a link you tap to install the plan, or let you do everything in their app.
5. Manual entry. Go to Settings > Cellular > Add Cellular Plan > Enter Details Manually and type in the details from your carrier.

Apple notes eSIM setup needs an internet connection, usually Wi-Fi, though eSIM-only models can activate without Wi-Fi in some countries. Moving from Android to iPhone usually means contacting your carrier, although Apple says some carriers support Android-to-iPhone eSIM transfers with iOS 26 or later.

How to set up an eSIM on Android

Menus vary by brand, but Google’s Pixel steps are typical:

1. Open Settings > Network & internet > SIMs.
2. Tap Add SIM, then Set up an eSIM.
3. Choose your carrier or scan the QR code they gave you.
4. Follow the prompts, then set which line handles calls, texts and data.

Samsung phones usually put this under Settings > Connections > SIM manager > Add eSIM. Many carriers also support converting a physical SIM to an eSIM on the same phone. AT&T, for example, publishes conversion steps for Pixel models and advises keeping the old physical SIM for a couple of weeks before throwing it away.

If you’re moving everything to a new handset at the same time, our checklist on how to transfer data to a new phone covers photos, apps and two-factor codes.

Where to start: a quick eSIM checklist

Before you switch, run through these 6 steps:

1. Confirm your phone supports eSIM using the model notes above.
2. Check that your phone is unlocked if you want a new carrier or a travel plan.
3. Back up your phone so a hiccup during activation doesn’t cost you anything. See how to back up your phone.
4. Connect to stable Wi-Fi before you start.
5. Get your activation method from the carrier: Quick Transfer, QR code, app or manual details.
6. Test it. Make a call, send a text and load a web page with Wi-Fi off. Then label each line (for example “Personal” and “Travel”) so you know which one is using data.

Tips for travelers

• Install your travel eSIM a day or 2 before you fly, but check when the plan’s validity clock starts. Some start on install, others on first connection.
• Turn on the travel line for data and leave your home line on for calls and texts only, with data roaming off.
• Delete expired travel eSIMs once you’re home so your list stays tidy.

Common problems

• “No service” after transfer: restart the phone and confirm the old SIM was deactivated.
• QR code won’t scan: ask the provider for manual details or an app activation link.
• Plan won’t install: the phone may be carrier-locked, or the carrier may not support your model.

Conclusion

An eSIM is simply a SIM card without the card. For most people, the payoff shows up at 3 moments: switching carriers, traveling abroad and setting up a new phone. Check that your phone supports it, make sure it’s unlocked if you need flexibility, and let your carrier’s QR code, app or transfer tool do the rest. If you’re setting up a device for someone else, such as a parent or child, our guides on setting up a phone for a senior and choosing a first phone for a kid cover what to configure next.

Sources

• GSMA: SGP.22 eSIM technical specification — consumer eSIM remote provisioning standard
• Apple Support: Set up eSIM on iPhone — setup methods, Quick Transfer requirements, iOS versions, number of stored eSIMs
• Apple Support: What is eSIM? — definition and security benefit
• Apple Support: Using Dual SIM with an eSIM — dual eSIM support and carrier unlocking
• Google Pixel Help: Use dual SIMs and eSIM — Pixel eSIM setup steps and eSIM-only US models
• FCC: Cell phone unlocking — locked vs unlocked phones and contacting your provider