How to install your eSIM

It takes about two minutes: scan the QR code on Wi-Fi at home, leave the new line switched off, and turn it on when you land. This guide covers iPhone, Android and Samsung step by step, what to do on arrival, and the fixes for the handful of things that go wrong.

Before you fly

Do the install at home on Wi-Fi. An airport with patchy Wi-Fi and a queue behind you is the wrong place to scan a QR code for the first time.

  1. 1
    Confirm your phone is eSIM-ready and unlocked
    Dial *#06# — an EID line means eSIM is supported. A carrier-locked phone will refuse the profile, so unlock it before you travel.
  2. 2
    Connect to Wi-Fi
    Installing downloads the profile from the carrier, so you need a stable internet connection. Home Wi-Fi is ideal.
  3. 3
    Open your order email or account page
    The QR code and the manual details (SM-DP+ address and activation code) are both there. Install on a different device? Show the QR on that screen.
  4. 4
    Plan to leave the new line OFF until you land
    Installing does not start the clock. On most plans validity begins the first time the eSIM connects to a network at your destination.

Install on iPhone

Works on iPhone XS/XR and newer. Menu names vary slightly by region — “Cellular” may read “Mobile Data” or “Mobile Service”.

  1. 1
    Settings → Cellular → Add eSIM
    Tap “Use QR Code” and point the camera at the code on another screen. Installing on the same phone? Screenshot the QR, then choose “Open Photos” on the scan screen (iOS 17+), or tap “Enter Details Manually” and paste the SM-DP+ address and activation code from your order page.
  2. 2
    Wait for “Cellular Plan Added”
    This can take a minute. Keep Wi-Fi on and do not leave the screen.
  3. 3
    Label the line “Travel”
    You will be asked which line is primary. Keep your home SIM as the default for calls and iMessage.
  4. 4
    Set “Cellular Data” to your home line for now
    You are still at home — leave data on the SIM you already use.
  5. 5
    Turn the Travel line OFF
    Settings → Cellular → Travel → toggle “Turn On This Line” off. It waits, unused, until you land.
  6. 6
    Leave Data Roaming alone for now
    You will switch it on for the Travel line only, once you arrive.

On iOS 17.4 and later, the “Install eSIM” button on your order page opens Settings directly with the profile pre-filled — no QR needed.

Install on Android

These are the stock Android steps (Pixel, Motorola, Sony, Nothing and most others). Samsung uses slightly different menus — see below.

  1. 1
    Settings → Network & internet → SIMs
    Tap “Add SIM” (or the + button). If it asks whether to download a SIM instead, say yes.
  2. 2
    Scan the QR code
    Point the camera at the code on another screen. Same phone? Choose “Enter code manually” (or “Need help?” → manual) and paste the activation code from your order page.
  3. 3
    Confirm the download
    Tap “Download” and wait — up to a minute on a slow connection. Keep Wi-Fi on.
  4. 4
    Name the SIM “Travel”
    Then choose which SIM is used for calls, messages and mobile data. Keep your home SIM for calls and messages.
  5. 5
    Leave the Travel SIM switched off
    Settings → Network & internet → SIMs → Travel → toggle “Use SIM” off. Turn it on when you land.

Samsung Galaxy

  1. 1
    Settings → Connections → SIM manager
    Tap “Add eSIM”, then “Scan QR code from service provider”. Manual entry is under “Enter activation code”.
  2. 2
    Wait for the profile to download, then name it “Travel”
    You will be asked which SIM handles calls, texts and mobile data. Keep your home SIM for calls and texts.
  3. 3
    Switch the Travel eSIM off until you land
    In SIM manager, toggle the Travel line off. Data roaming for it is under Settings → Connections → Mobile networks.

When you land

Four toggles, in this order, and you are online. Give the phone a minute to register on the local network after the last one.

  1. 1
    Turn the Travel line on
    iPhone: Settings → Cellular → Travel → “Turn On This Line”. Android: SIMs → Travel → “Use SIM”. Samsung: SIM manager → Travel.
  2. 2
    Set Travel as the line for mobile data
    iPhone: Settings → Cellular → Cellular Data → Travel. Android/Samsung: SIMs or SIM manager → Mobile data → Travel.
  3. 3
    Turn Data Roaming ON — for the Travel line only
    This is the step everyone misses. A travel eSIM roams by design; without it you get bars but no internet. Leave roaming OFF on your home SIM so it cannot bill you.
  4. 4
    Toggle Airplane Mode once and wait
    Forces a fresh network registration. Within a minute you should see the local network name and a 4G/5G icon.

Good to know

Each QR code installs once — do not delete the eSIM from your phone mid-trip, and do not try to add it to a second phone. Your home number keeps working for calls and texts on your physical SIM; WhatsApp and iMessage carry on over the travel data.

Troubleshooting

Almost every problem is one of these. Work through the matching one before contacting support — and if you do write to us, include your order number and a screenshot of the Cellular/SIM settings screen.

I can’t scan the QR code — it’s on the same phone

Take a screenshot of the QR. On iPhone (iOS 17+) the Add eSIM scanner has an “Open Photos” option; pick the screenshot. On any phone, use manual entry instead: copy the SM-DP+ address and activation code from your order page into “Enter Details Manually” (iPhone) or “Enter code manually” (Android).

“This code is no longer valid” or “eSIM already installed”

A QR code installs exactly once. If the profile is already on your phone, it is in Settings → Cellular (or SIM manager) — do not add it again. If it was deleted, it cannot be reinstalled from the same code; email support with your order number.

Install hangs, or “Unable to complete cellular plan change”

Switch to a stronger Wi-Fi network, restart the phone and try again. If it fails the same way twice, the phone is usually carrier-locked — check Settings → General → About → Carrier Lock on iPhone, or contact your home carrier.

I landed and have signal bars but no internet

Data Roaming is off for the travel line, or the phone is still using your home SIM for data. Set Cellular Data / Mobile data to Travel, then turn Data Roaming ON for that line specifically. Toggle Airplane Mode once afterwards.

“No Service” or “Searching…” after switching the line on

Registration can take a minute or two after landing. Toggle Airplane Mode. If it persists, go to Settings → Cellular → Travel → Network Selection (Android: Mobile network → Network operators) and make sure it is on Automatic — or pick a network from the list manually.

It works but feels slow

Try a different spot — indoor coverage varies a lot. Check the plan label: some plans reduce speed after the allowance is used. Turn off any VPN and iPhone Low Data Mode, and make sure the Travel line, not your home SIM, is selected for data.

I deleted the eSIM by mistake

A deleted profile cannot be restored from the same QR code. Email info@onetapsim.com with your order number before doing anything else — do not buy another plan yet.

Install questions

Can I install the eSIM days before I travel?

Yes — that is the recommended way. Install at home on Wi-Fi, leave the line switched off, and turn it on when you land. On most plans the validity period starts on first connection at the destination, not at install.

Does installing start my plan?

Usually not. Validity starts when the eSIM first connects to a network at your destination. The exception is a plan whose description says it starts on purchase — the plan page says so.

Can I put the same eSIM on two phones?

No. A QR code installs on one device, once. If you switch phones mid-trip, contact support with your order number.

Will my normal number still work abroad?

Yes, on your physical SIM, for calls and texts as your home carrier allows. The travel eSIM carries data only. Keep Data Roaming OFF on the home SIM so it cannot bill you, and ON for the travel line.

Should I delete the eSIM after the trip?

You can leave it installed at no cost; it simply stops working when the plan ends. If you reuse OneTapSIM for another trip you will receive a new QR code — the old profile can be removed to keep the list tidy.

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How to install your eSIM · OneTapSIM