Must-Know eSIM Precautions for Travel

TL;DR (4 essentials)

• Data on eSIM, keep home number on USIM (dual SIM)
• Data roaming OFF on home USIM
• eSIM often cannot be reinstalled after deletion
• Install/register on Wi‑Fi, don’t leave the screen or close the app during install

1) “Standard” setup to avoid high roaming

Do both:

A. Mobile data line = eSIM

If data is still on home USIM, you may get roaming charges.

B. Home USIM data roaming = OFF

Steps: /guide/domestic-sim-roaming-off (iPhone / Galaxy).

2) Finish eSIM install in one go

• QR/codes are often one-time use.
• During install, avoid back/close/leaving the screen.
• Don’t delete eSIM while traveling; use turn off (disable) if needed.

3) Install on Wi‑Fi, finish before departure

Unstable airport/hotel Wi‑Fi can cause install issues. Finish on stable Wi‑Fi before you leave.

4) Data-only plans in practice

Travel eSIM is often data-only.

• Keep home USIM for calls/SMS
• Use eSIM for data

5) Check data/speed policy

• High-speed nGB then throttled unlimited?
• Fully unlimited?
• Daily cap?
• Tethering allowed?

Data amount: /guide/esim-data-amount-guide

Pre-departure checklist (copy and use)

• eSIM installed (stable Wi‑Fi)
• Mobile data line = eSIM
• eSIM data roaming ON
• Home USIM data roaming OFF
• QR / order number / activation code saved