How to Activate an eSIM on iPhone: A Step-by-Step Guide for Travelers

2026-10-23 · Flylo

An eSIM is a digital SIM built into your iPhone. Instead of hunting for a SIM shop at the airport or paying your carrier's daily roaming rate, you buy a data pack online, install it in a few minutes, and your phone connects to a local network when you land. This guide walks through the whole process on an iPhone, in the order that works best: set everything up at home, then switch it on when you arrive.

Before you start: two quick checks

1. Your iPhone supports eSIM

Every iPhone from the XS, XS Max, and XR onward (2018 and later) supports eSIM. iPhones sold in the US from the iPhone 14 onward are eSIM-only, so they definitely qualify. If you have an older model, check under Settings → General → About for an "Available SIM" or eSIM IMEI entry.

2. Your iPhone is carrier-unlocked

This is the step people miss. A travel eSIM only works if your phone is not locked to your home carrier. Go to Settings → General → About and look for Carrier Lock. If it says "No SIM restrictions," you are good. If it shows a carrier name, your phone is locked — contact your carrier about unlocking it before you buy any eSIM. Phones bought on a payment plan are often locked until they are paid off.

Step 1: Buy your data pack before you fly

Buy while you are still home, on your normal connection. You pick a destination, a data amount, and a validity window, pay online, and receive an email with installation details — usually a QR code and a backup activation code. Do not wait until you land: airport Wi-Fi is unreliable, and installing an eSIM requires an internet connection.

One timing tip matters here. On most travel packs, the validity clock starts when the eSIM first connects to a network at your destination, not when you buy it — but a few start at installation. Check the pack's terms, and when in doubt, install a day or two before departure and simply leave the line switched off until you land.

Step 2: Install the eSIM (do this at home, on Wi-Fi)

• Open the email with your QR code on a second screen or print it out — you cannot scan a code displayed on the same phone.
• On your iPhone, go to Settings → Cellular (called Mobile Data on some regions' phones) → Add eSIM.
• Choose Use QR Code and scan the code with your camera.
• Follow the prompts to add the plan. It takes about a minute.

No QR code handy? Most providers, Flylo included, also send an install link or manual details. In the same Add eSIM flow, tap Enter Details Manually and paste in the SM-DP+ address and activation code from your email. After checkout at flylo.co, your eSIM and its install details also live in your My eSIMs library, so the email is not the only copy.

Step 3: Label your lines

Your iPhone will ask you to label the new plan. Call it something obvious like Travel or the destination name. Your existing line keeps the Primary label. Clear labels matter, because in the next step you will tell the phone which line does what — and "Plan 2" is a confusing name to be staring at in an airport.

Step 4: Set which line does what

Still in Settings → Cellular:

• Default Voice Line: leave this on Primary. Your US number stays in charge of calls and regular texts, so the people (and banks) who reach you on it still can.
• Cellular Data: set this to your Travel line once you arrive. Before departure, you can leave it on Primary.
• Allow Cellular Data Switching: turn this off. With it on, your phone may quietly hop back to your US line for data — which is exactly how surprise roaming bills happen.
• Data Roaming: tap your Travel line and turn Data Roaming on. This sounds backwards, but travel eSIMs almost always need roaming enabled to connect to their partner networks. You will not be charged by your US carrier for this, because the roaming toggle that matters for billing is on your Primary line — keep roaming off there.

Step 5: Activate on landing

When your plane lands, turn off Airplane Mode, go to Settings → Cellular, make sure the Travel line is turned on and selected for Cellular Data. Give it a minute or two to register on a local network. You should see the signal switch to a local carrier name and data start working. That is it — maps, rideshare, messaging, all live before you reach the baggage claim.

If something does not connect

• No service: confirm the Travel line is on, selected for data, and that Data Roaming is on for that line specifically.
• Still stuck: toggle Airplane Mode for 30 seconds, or restart the phone — registration hiccups are usually fixed by re-registering on the network.
• Data works but slowly at first: give it a few minutes; some networks take a moment to provision full speed.

Ready to pick a pack? Browse data packs for your destination on the destinations page, install it tonight, and let future-you walk off the plane already connected.