You have heard of eSIMs but are not sure exactly what they are, whether your phone supports them, or how complicated the setup actually is. Here is the complete honest explanation for first-time eSIM users.
What an eSIM Actually Is
Your phone has a SIM card slot — a tiny tray you pop open with a pin and slide a physical card into. That card tells your phone which carrier network to connect to. An eSIM does the same thing but digitally. Instead of a physical card you can touch and lose, the eSIM is a chip already soldered inside your phone from the factory. You download a data plan onto it by scanning a QR code. No physical swap, no tiny card, nothing to lose at the airport.
Does Your Phone Support eSIM?
| Phone | eSIM support | Check here |
|---|---|---|
| iPhone XS, XR or newer (2018+) | ✅ Yes | Settings, General, About — look for EID number |
| iPhone 14 or newer (US models) | ✅ eSIM only (no physical SIM slot) | eSIM only — no physical tray |
| Samsung Galaxy S20 or newer | ✅ Most models yes | Settings, Connections, SIM Manager — look for eSIM option |
| Google Pixel 3 or newer | ✅ Yes | Settings, Network, SIMs — look for Download SIM option |
| Samsung bought in China or Korea | ⚠️ Some models do not support eSIM | Check Settings, Connections, SIM Manager specifically |
| Any phone bought before 2018 | ❌ Likely not | Check EID in settings — if no EID, no eSIM support |
Is Your Phone Carrier-Unlocked?
Even if your phone supports eSIM, it may be carrier-locked — meaning it only accepts SIM cards from one specific carrier (like AT&T or Vodafone UK). A carrier-locked phone cannot install international eSIM plans. Check: Settings, General, About on iPhone — if you see Carrier Lock: No SIM restrictions, you are unlocked. If you see a specific carrier name under Lock, contact your carrier to unlock it before your trip.
Setup in 3 Steps
Step 1 — Purchase: Buy your travel eSIM online. You receive a QR code by email within minutes.
Step 2 — Install at home (before your trip):
iPhone: Settings, Cellular, Add eSIM, Use QR Code, scan the QR code. Your phone downloads the plan. Label it Japan Data or China Data so you know which line it is.
Android: Settings, Network, SIMs, Download SIM, scan QR code.
Step 3 — On landing: Disable Airplane Mode. Go to Settings, Cellular, tap your travel eSIM line, enable Data Roaming. Done — you are connected.
Dual SIM: Keep Your Home Number Active
This is the part most beginners do not realize: your original SIM card stays in the phone. The eSIM is a second line added alongside it. Your home number stays active for calls, SMS, and bank 2FA verification codes. Your travel eSIM provides the data connection. Both work simultaneously. You do not need to remove your existing SIM card for an eSIM to work.
Three Common Beginner Questions
What if the QR code does not scan? Make sure you are on stable home WiFi (not mobile data) when scanning. Point the camera directly at the QR code in good lighting. If the scan fails: in Settings, Cellular, Add eSIM, there is usually an option to Enter Details Manually — your eSIM provider can give you a manual activation code as an alternative.
I have signal but no internet — what happened? The most common cause: Data Roaming is off. Settings, Cellular, tap your travel eSIM line, Data Roaming — turn it on. This is the fix for 80% of eSIM connectivity issues after landing.
Can I install more than one eSIM? Yes. Modern phones can store multiple eSIM profiles. If you visit Japan and then South Korea on the same trip, you can install both eSIM profiles before departure and switch between them in settings when you cross the border.
FAQ
Is eSIM setup difficult for non-technical people?
It is simpler than setting up a new app. The process is: open Settings, tap a few menus, point camera at a QR code, wait 60 seconds. If you have ever connected to a new WiFi network, you can install an eSIM. The step that confuses most people is enabling Data Roaming after landing — which is one toggle switch in one settings menu.
What if I bought my phone in China?
Many phones sold in mainland China (including some iPhone models and Samsung Galaxy models) do not support eSIM or have eSIM functionality disabled. Check for an EID number in Settings, General, About on iPhone. If no EID is present: the phone does not support eSIM and you would need a physical SIM card for international travel data.
Can I use an eSIM and keep my regular SIM active?
Yes — this is the main advantage over swapping SIM cards. Your original SIM stays in the phone. The eSIM is a second digital line. Calls and SMS on your home number, data from your travel eSIM. Both active simultaneously on the same phone.
Ready to try your first eSIM? Japan eSIM from $1.49 is the most straightforward first eSIM experience — Docomo network, instant QR code, works from the gate at Narita.