Your flight to Tokyo leaves in 6 hours. You just remembered you need mobile data when you land. Your friend mentioned something about eSIM being “super easy”—just scan a code and you’re done. But you’ve never done it before. Is it actually simple? What if something goes wrong at midnight in Narita Airport?
Here’s the truth: eSIM installation takes 3 minutes when you know what you’re doing. But if you skip one small step—like enabling Data Roaming for the eSIM line specifically—you’ll spend 20 frustrated minutes wondering why your phone shows “No Service” despite following every instruction.
This guide walks through the complete eSIM installation and activation process for both iPhone and Android devices. Not the sanitized version that skips the confusing parts. The real version that addresses the specific steps where people actually get stuck.
Before You Start: Three Critical Checks
Check 1: Does Your Phone Support eSIM?
Don’t assume. Verify.
| Device Type | Supported Models / Requirements |
|---|---|
| iPhone | iPhone XS or newer (XS, XR, 11, 12, 13, 14, 15 series and newer). Check: Settings > Cellular > Add Cellular Plan. |
| Android | Samsung Galaxy S20/S21/S22/S23/S24, Google Pixel 3-8, Galaxy Z Fold/Flip 3-5, select Motorola/Oppo/Huawei. Check: Settings > Network & Internet > SIMs > Add/Download SIM. |
If your phone doesn’t support eSIM, you need a physical SIM card. No workaround exists.
Check 2: Is Your Phone Unlocked?
Carrier-locked phones reject eSIM profiles from third-party providers like RedEx eSIM.
| Platform | How to Check |
|---|---|
| iPhone | Settings > General > About > Carrier Lock. Must say “No SIM restrictions”. |
| Android | Settings > About Phone > Status > SIM Lock Status. Must say “Unlocked”. |
How to unlock: Contact your carrier. The process typically takes 24-48 hours after approval.
Check 3: Do You Have WiFi or Mobile Data?
eSIM installation requires downloading a carrier profile (less than 5MB). Use WiFi at home or airport WiFi/home carrier data upon arrival.
Installing eSIM on iPhone: Complete Process
| Step | Action | Details |
|---|---|---|
| 1 | Purchase Plan | Buy via RedEx eSIM website/app. Save the email with QR code and activation code. |
| 2 | Open Settings | Settings > Cellular (or Mobile Data) > Add Cellular Plan (or Add eSIM). |
| 3 | Scan QR Code | Scan from another device or tap “Enter Details Manually” (SM-DP+ Address & Activation Code). |
| 4 | Download Profile | Tap Continue when “Cellular Plan Detected” appears. Wait 10-30 seconds. |
| 5 | Label eSIM | Choose “Travel” or custom label like “Japan Travel”. |
| 6 | Configure Lines | Set “Cellular Data” to eSIM and “Default Line” (Calls/iMessage) to your physical SIM. |
| 7 | Enable Data Roaming | Critical: Tap eSIM line > Turn “Data Roaming” ON (Green). |
| 8 | Stay Disabled | Keep “Turn On This Line” OFF until you arrive at your destination. |
Installing eSIM on Android: Complete Process
| Step | Action (Samsung / Pixel) | |
|---|---|---|
| 1 | Purchase Plan | |
| 2 | Open SIM Settings | Settings > Connections > SIM manager (Samsung) or Network & Internet > SIMs (Pixel). |
| 3 | Add eSIM | Tap “Add mobile plan” or the “+” icon. |
| 4 | Scan / Manual | Scan QR from another device or “Enter activation code” manually. |
| 5 | Download | Wait 15-45 seconds for the profile to download and activate. |
| 6 | Label & Configure | Set Name/Label (e.g., “Europe Data”) and set Mobile Data to the new eSIM. |
| 7 | Data Roaming | Critical: Find “Roaming” in eSIM settings and turn it ON. |
| 8 | Disable | Toggle eSIM to OFF until you reach your destination. |
Activating Your eSIM at Your Destination
| Platform | Activation Steps |
|---|---|
| iPhone | Settings > Cellular > eSIM line > Toggle “Turn On This Line” ON. Wait 30-60s for signal. |
| Android | Settings > SIM manager > eSIM > Toggle ON/Enabled. Wait 30-60s for signal. |
Troubleshooting: When Things Don’t Work
| Problem | Common Cause & Solution |
|---|---|
| “No Service” | Data Roaming is OFF. Solution: Turn Data Roaming ON in eSIM settings. Or toggle Airplane Mode. |
| Signal but No Data | Wrong line selected. Solution: Settings > Cellular Data > Select eSIM line. |
| “Cannot Be Added” | Phone is carrier-locked or QR code already used. Solution: Contact carrier or provider. |
| Slow/Intermittent | Weak network. Solution: Turn off “Automatic” in Network Selection and manually pick a carrier. |
| No Calls | Normal for data-only eSIMs. Solution: Keep physical SIM enabled for calls/SMS. |
| Invalid Code | Typo in manual entry. Solution: Copy/paste SM-DP+ and Activation Code directly from email. |
| eSIM Disappeared | Accidentally deleted. Solution: Reinstall with original QR or contact support. |
Advanced Tips
Installing Multiple eSIMs
Phones can store 5-10 profiles. Install all plans (e.g., Japan, Thailand, Singapore) before leaving and enable/disable them as you cross borders.
Checking Data Balance
| Method | Details |
|---|---|
| Provider App | Check via RedEx eSIM app or dashboard (Recommended). |
| System Settings | Cellular/Data Usage settings show total consumption (not remaining balance). |
Buying More Data
Most providers like RedEx eSIM allow “Top Ups” directly in the app without needing to scan a new QR code.
Removing Old Profiles
Go to SIM/Cellular settings, select the expired eSIM, and tap “Remove/Delete Cellular Plan”.
Why eSIM Installation is Easier Than It Seems
| Method | Total Time Investment |
|---|---|
| eSIM Process | 5 minutes total (Purchase + Scan + Setup). |
| Physical SIM | 35-90 minutes (Find store + Wait in line + Manual activation). |
Final Checklist Before Your Trip
- ✅ Verify eSIM support & carrier unlock status.
- ✅ Purchase and install profile before departure.
- ✅ Enable Data Roaming for the eSIM.
- ✅ Keep eSIM disabled until you land.
- ✅ Save support contact info.
For your next trip, try RedEx eSIM. Coverage in 195+ countries. Activation in under 60 seconds.