Coral eSIM

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eSIM Installation Guide

※The following steps are for adding and activating a new eSIM profile on an eSIM-compatible smartphone without replacing the physical SIM. Please confirm in advance that your device is "SIM-unlocked/eSIM-compatible."

Common Preparation (iOS/Android)

  1. Confirm Compatible Device and Network

    • Check that your device supports eSIM (model number, OS version, carrier restrictions, etc.).

    • Your smartphone must be in a "SIM-free" state (not locked to a carrier), or allow eSIM use from external carriers.

    • For overseas use, it is recommended to ensure an environment (Wi-Fi, etc.) where you can install and activate the eSIM profile before departure.

  2. Prepare QR Code

    • Prepare the "QR code for eSIM profile installation" sent by the eSIM provider. The QR code should be readable in any format (paper, email, PDF, etc.).

    • A stable internet connection (Wi-Fi, etc.) when scanning the QR code will make the process smoother.

  3. Confirm Physical SIM/Communication Settings

    • Decide in advance whether to continue using your existing physical SIM or add a new eSIM as a secondary line, and how to use each (calls/data) to make setup smoother.

    • It's reassuring to check roaming settings, data communication settings, and airplane mode activation before departure.

iOS (iPhone/iPad) Instructions

⚠️ 【Critical】After installing your eSIM, you MUST turn on "Data Roaming"

Settings app → Cellular / Mobile Data → select the eSIM line you added → turn "Data Roaming" ON

Without this setting, your eSIM will not be able to connect to mobile data overseas. Our eSIM connects to local carriers via "roaming", so Data Roaming is required. No additional charges apply — you can safely turn it on.

Prerequisites

  • iOS 13 or later (varies by model) with eSIM support.

  • Use the "Settings" app.

Steps

  1. Prepare QR Code

    • Have the QR code from your guide email/PDF ready to display (e.g., on another device's screen, printed material, screenshot, etc.).

  2. Open the "Settings" app → Go to "Cellular" or "Mobile Data".

  3. Tap "Add Cellular Plan" or "Add Plan".

  4. When a menu like "Install using eSIM" or "Use QR Code" appears, the camera screen for scanning the QR code will be displayed.

    • Scan the QR code with your smartphone camera.

    • After scanning is complete, the cellular plan profile will be downloaded and prepared.

  5. Confirm and set the plan name, line type (primary/secondary), default voice, data, and roaming settings.

    • For example, set "Use secondary line (eSIM) for data only" or "Continue using physical SIM for calls + text" according to your needs.

  6. Tap "Add Cellular Plan" to confirm the profile.

  7. 【Required】Turn on "Data Roaming" (most critical step)

    • Go to "Settings" → "Cellular" → tap the name of the eSIM line you added → turn "Data Roaming" ON.

    • On the same screen, also make sure "Turn On This Line" is enabled.

    • Return to "Settings" → "Cellular" and confirm that "Cellular Data" points to the eSIM you added (if you want to use the eSIM for data).

    • Skipping this step will prevent your eSIM from connecting overseas. See the "Essential Setting After Installation: Turn On Data Roaming" page for details.

  8. Restart the device if necessary.

  9. Confirm that communication is possible (internet browsing, etc.). It's reassuring to test whether data communication works at your destination by turning off Wi-Fi.

Additional Notes

  • After adding eSIM, if you continue using the physical SIM, clearly setting the purpose (e.g., "calls/SMS" vs "data") will improve convenience.

  • For eSIMs used overseas, completing installation before departure is recommended, as communication is often possible immediately upon arrival.

  • Keep Wi-Fi connected while the installation process is running after scanning the QR code.

  • The UI for switching "Primary Line" and "Secondary Line Activation" varies by device, so it's reassuring to familiarize yourself with the setup procedure.

Android Instructions

Prerequisites

  • Android 10 or later, or an eSIM-compatible device/OS.

  • Steps may vary slightly by manufacturer (Samsung, Google Pixel, Xiaomi, etc.).

  • Here we explain the general flow, but please also check your device's manual or official website.

Steps

  1. Prepare QR Code

    • Similar to iOS, prepare to display the QR code from your guide email/PDF.

  2. Open the "Settings" app → Go to "Network & Internet" or "Connections & Sharing" or similar.

  3. Select "SIM Cards/Mobile Network" or "Mobile Network" → "Add eSIM" or "Add Cellular Plan" or similar menu.

  4. Tap "Scan QR Code" or "Load eSIM Profile" and scan the QR code with your camera.

    • After recognition, the eSIM profile download and setup will start automatically.

  5. When an option to "Activate" or "Start" the line appears, grant permission.

  6. Confirm and set the line name, purpose (e.g., data only/calls and data), and priority line settings.

    • It's easier to organize by separating purposes, such as using the main line for physical SIM and the newly added eSIM as a secondary line.

  7. Set "Data Communication Line" and "Mobile Data Roaming":

    • Set "Mobile Data" to use the eSIM line.

    • Turn "Roaming" ON if necessary.

  8. After setup is complete, enable the eSIM line and restart the device, or confirm that communication is possible.

    • Turn off Wi-Fi and test whether internet connection is possible.

  9. For overseas use, it's reassuring to complete activation before departure.

Additional Notes

  • The screen for switching "Default Line" and "Priority Line" varies by Android device. Look for terms like Settings → Line Management → Priority Line.

  • If you keep the physical SIM, clearly set which line to use for calls and which for data.

  • After eSIM installation, you may need to check "APN" auto-loading/manual settings in the device's mobile network settings. Follow the provider's instructions.

  • We strongly recommend installing and testing communication in a stable Wi-Fi environment before departure (to prevent cases where communication is not possible immediately upon arrival overseas).

Troubleshooting & Tips

  • If QR code scanning doesn't work or shows an error:

    • Try adjusting the camera focus.

    • If the QR code screen is too bright or reflective and can't be read, use another screen or printed version.

    • If the QR code is old and expired, request reissuance from the provider.

  • If the line doesn't activate or communication doesn't work:

    • Check if eSIM is "ON" and which line (physical SIM/eSIM) is prioritized.

    • Check if data roaming settings are "OFF".

    • Check if airplane mode is disabled.

    • Check if OS and carrier settings are the latest version.

    • Check if the device is "SIM-free (unlocked)".

  • Notes for overseas use:

    • It's reassuring to complete installation and activation before departure. If communication is not possible at the destination, it may cause issues with maps, transportation guides, hotel check-ins, etc.

    • Check data usage and remaining balance frequently, and understand whether additional charging is possible.

    • For "data-only eSIM" without calls/SMS, you should prepare a separate line for services that require SMS authentication or calls (banks, shopping, etc.).

  • Note that eSIM reissuance is not possible if you lose or replace your device.