The eSIM is steadily replacing the familiar plastic SIM card. If you are about to travel abroad or want to use two numbers on one phone, this is the complete eSIM guide, written for people who have never used one before.
What is an eSIM?
An eSIM (short for embedded SIM) is a SIM chip built into your phone at the factory. Instead of buying a plastic card and slotting it in, you simply scan a QR code and the plan is loaded straight onto your device. No swapping, no risk of losing it, no SIM-ejector pin needed.
Technically an eSIM works exactly like a regular SIM: it has a subscriber number, connects to 4G/5G, and makes calls and texts (depending on the plan). The only difference is that it lives inside the phone and is activated by software.
How is an eSIM different from a regular SIM?
| Criteria | Physical SIM | eSIM |
|---|---|---|
| Form | Loose plastic card | Chip built into the phone |
| How you get it | Visit a store / wait for delivery | QR code by email instantly |
| Time to get online | Must insert the card | Scan QR, ~2 minutes |
| Numbers per phone | 1–2 slots | Stores many profiles, switch freely |
| Risks | Drop, break, swap the card | No card to lose |
Why should travellers use an eSIM?
- Online the moment your plane lands – activate it at home and you are connected as soon as you power on, no queueing for a SIM at the airport.
- Keep your Vietnamese number – to receive bank OTPs and Zalo messages, while the eSIM handles your 4G/5G data.
- Cheaper and clearer than roaming – no surprise sky-high bills after the trip.
- No need to change cards between countries – one regional eSIM covers several countries.
Which phones support eSIM?
Most recent models do. The most common are:
- iPhone: iPhone XR / XS and later (XS, 11, 12, 13, 14, 15, 16…).
- Samsung: Galaxy S20 and later, the Z Fold/Z Flip series, Note 20…
- Google Pixel: Pixel 3 and later.
- Oppo, Xiaomi, Huawei: some recent high-end models.
Quick check: go to Settings → About; if you see an EID entry (a long string of digits) your phone supports eSIM. Note that the phone must be carrier-unlocked.
How do you buy and activate an eSIM?
- Choose your destination and a data plan that matches the length of your trip.
- Pay and receive the QR code by email instantly.
- Go to Settings → Cellular/SIM → Add eSIM and scan the QR code.
- Turn the eSIM on before you depart; you will have signal as soon as you arrive.
See every step in How to install & activate an eSIM on iPhone and Android.
Where to buy an eSIM
Go365 offers eSIMs for more than 130 countries and territories – from Korea, Japan and Thailand to Europe and the USA – with many data sizes and validity periods to match your needs. Receive the QR code instantly and activate it in 2 minutes.