eSIM Explained: Set Up and Transfer an eSIM on iPhone and Android

An eSIM does exactly what a plastic SIM card does — it proves to a network that you’re a paying subscriber — but it lives inside a chip soldered to the phone’s board. There’s nothing to insert or lose. Instead, your carrier sends a profile that the phone downloads and stores.

That convenience comes with new questions. How does the carrier know which phone to send the profile to? What happens when you upgrade, reset or sell? And why does an eSIM from another carrier fail on some second-hand phones? This guide covers the mechanics, the exact steps on iPhone and Android, and the edge cases that catch people out.

How eSIM actually works: EID, profiles and SM-DP+

Three pieces make an eSIM work:

• The eUICC chip and its EID. The embedded chip has a 32-digit identifier called the EID. It identifies the chip, not the phone or the subscription. The IMEI still identifies the phone on the network. Our guide to IMEI vs serial vs MEID vs EID explains how they differ.
• The profile. This is the digital equivalent of a SIM card: your number, network keys and settings. A phone can store several profiles but typically uses one or two at a time.
• The SM-DP+ server. The carrier’s provisioning server that prepares your profile and delivers it, securely, to one specific eUICC.

Every activation method below is just a different way of telling the phone where the SM-DP+ server is and which profile to collect.

Find your EID and IMEI

On most eSIM-capable phones the dialer code shows both:

*#06#

On iPhone you can also go to Settings › General › About and scroll to EID. On Android it’s usually under Settings › About phone (on Samsung, often in Status information). Carriers sometimes ask for the EID when issuing an eSIM remotely.

Four ways to activate an eSIM

Set up an eSIM on iPhone

1. Connect to Wi-Fi.
2. Open Settings › Cellular (Mobile Data in some regions) › Add eSIM.
3. Choose Use QR Code and scan it, or tap “Enter Details Manually” to type the SM-DP+ address and activation code.
4. If your carrier used carrier activation, a notification “Carrier Cellular Plan Ready to Be Installed” appears instead — tap it.
5. Label the line (Personal, Business, Travel) and choose the default line for calls, iMessage and data.

Some carriers also let you convert a physical SIM to eSIM in Settings › Cellular, by tapping the line and choosing “Convert to eSIM”. If the option isn’t there, your carrier doesn’t support it on that plan.

Transfer an eSIM to a new iPhone (eSIM Quick Transfer)

Since iOS 16, iPhones can move an eSIM directly between devices, provided the carrier supports it:

1. Keep the old iPhone nearby, unlocked, with Bluetooth on, and signed in to the same Apple Account.
2. On the new iPhone, during setup or from Settings › Cellular › Add eSIM, choose Transfer From Nearby iPhone.
3. Confirm on the old iPhone, and enter any code the new one shows.
4. Wait for activation. The line stops working on the old iPhone once it moves.

Recent iOS versions also support moving an eSIM between an iPhone and an Android phone with some carriers, but support is limited. If Quick Transfer isn’t offered, the carrier will issue a new eSIM via its app, website or a QR code.

Set up and transfer an eSIM on Android

Android menus differ by brand and version, so treat these as typical paths:

• Google Pixel: Settings › Network & internet › SIMs › Add SIM (or “+”), then “Download a SIM instead?” and scan the QR code.
• Samsung Galaxy: Settings › Connections › SIM manager › Add eSIM, then scan the QR code or use the carrier’s option.
• Other brands: look under Mobile network or SIM settings for “Add eSIM” or “Download SIM”.

Transfers are where Android varies most. Newer Pixel and Galaxy models can move an eSIM from an old phone during setup with supported carriers, using an on-screen code or a QR scan. Older phones, smaller brands and many carriers outside the US and Europe still require a fresh profile from the carrier. If your phone or carrier doesn’t offer a transfer option, ask the carrier for an eSIM replacement — it’s usually quick, but it involves identity checks, which is exactly what protects you from scams and SIM-swap fraud.

eSIM and carrier-locked phones

An eSIM doesn’t bypass a carrier lock. A locked phone checks every profile against its lock policy, exactly as it checks a physical SIM:

• A locked iPhone will only accept eSIMs from its carrier (and any networks its policy allows). Other carriers’ profiles typically fail to install or show “SIM Not Supported” / “This eSIM can’t be added”.
• Some locked Android phones download a foreign profile but won’t connect, or show a network lock prompt.
• US iPhone 14 and later are eSIM-only, so you can’t test them with a borrowed SIM card — the lock status matters even more.

So check before you buy, before you travel and before you pay for a travel eSIM. A carrier + SIM-lock check shows the carrier and lock status of an iPhone, a SIM-lock status check gives a fast yes/no, and the SIM-lock check by IMEI or serial works when you only have the serial. Our guide on checking if an iPhone is unlocked explains how to read the result.

Troubleshooting eSIM problems

• “Unable to complete cellular plan change”: usually a used or expired QR code, or a weak connection. Use stable Wi-Fi and ask the carrier to reissue.
• eSIM installed but “No Service”: check the line is turned on, the right line is selected for data, and roaming is enabled for travel eSIMs.
• “This code is no longer valid”: the profile was already downloaded to another device. Only the carrier can release a new one.
• Profile won’t install on a second-hand phone: suspect a carrier lock or a blocked IMEI. A GSMA blacklist check rules out the latter.
• Need the full device picture? The All-in-one basic info report confirms the exact model, which matters because not every regional variant supports eSIM. The carrier check page lists every lock check we offer.

Verdict

eSIM is simpler than a plastic card once you understand the pieces: the EID identifies the chip, the carrier prepares a profile, and the phone downloads it — as long as the phone’s lock policy allows that carrier. Before buying a used phone or a travel plan, confirm the lock status with the IMEI below: