Installing vs. Activating: They're Different Steps

This is the most important thing to understand about using an eSIM for travel:

• Installing = downloading the eSIM profile onto your phone. Check when your plan starts before doing this.
• Activating = turning on the eSIM line so it connects to a network. The best time to do this depends on your plan type (see below).

If you haven't installed your eSIM yet, start with our installation guides for iPhone or Android first, then come back here.

Why does the timing matter? Most travel eSIM plans have a validity window (e.g., 7 days, 14 days, 30 days). When that window starts counting depends on your plan:

• Instant activation plans: Validity starts when the eSIM profile is downloaded/installed. For these plans, it is especially important not to install too early before your trip, since the clock is already ticking.
• Activation upon arrival plans: Validity starts when the eSIM first connects to a cell tower in the destination country. For these plans, you can safely install at home — the clock won't start until you land.

Check your plan details on your order page before installing. If the timing is unclear, contact support first. Keeping the line turned off does not pause a plan whose validity starts at installation.

Activate on iPhone

1. Open Settings
2. Tap Cellular (or Mobile Data)
3. You'll see a list of your cellular plans — tap the eSIM plan you installed (it should show the label you gave it, like "Japan Travel")
4. Toggle Turn On This Line to enable it
5. Go back to the Cellular settings screen
6. Tap Cellular Data (at the top of the plan list)
7. Select your eSIM plan as the line used for cellular data
8. Go back, then tap your eSIM plan again
9. Toggle Data Roaming to on

That last step is critical. Travel eSIMs work via roaming agreements with local carriers. If Data Roaming is off, you'll see the eSIM as active but you won't get any data connection.

Here's what the eSIM detail page looks like. Make sure "Turn On This Line" is enabled.

Toggle Data Roaming ON — this is required for travel eSIMs.

You'll see "Setting Up Cellular" while your eSIM connects to the network.

Activate on Google Pixel and Stock Android

1. Open Settings
2. Tap Network & Internet
3. Tap SIMs
4. Tap your eSIM plan
5. Toggle the switch at the top to turn it on
6. Tap Data Roaming and toggle it on
7. Go back to the SIMs screen
8. Tap Preferred SIM for data (or a similar option)
9. Select your eSIM plan as the default data line

Activate on Samsung Galaxy

1. Open Settings
2. Tap Connections
3. Tap SIM manager
4. Under your list of SIMs, tap the eSIM you installed
5. Toggle the switch to turn it on
6. Back in SIM manager, tap Mobile data
7. Select your eSIM as the line for mobile data
8. Go to Settings > Connections > Mobile networks
9. Toggle Data Roaming to on

Set Your eSIM as the Default Data Line

This step is easy to overlook but it's essential. Your phone needs to know which SIM card to use for internet data. If your primary SIM is still set as the default data line, your phone will try to use that instead of your travel eSIM — which means roaming charges on your home plan.

On iPhone: Settings > Cellular > Cellular Data > select your eSIM plan.

On Android: Settings > Network & Internet > SIMs > Preferred SIM for data > select your eSIM.

On Samsung: Settings > Connections > SIM manager > Mobile data > select your eSIM.

Troubleshooting: No Connection After Activation

If you've turned on your eSIM and enabled Data Roaming but still can't get online, try these steps in order:

1. Toggle Airplane Mode. Turn Airplane Mode on, wait 10 seconds, then turn it off. This forces your phone to re-scan for available networks.

2. Restart your phone. A full restart clears any temporary connection issues. Power off completely, wait a few seconds, and power back on.

3. Check network selection. Go to your phone's network settings and make sure it's set to Automatic network selection (not manually locked to a specific carrier).

4. Confirm you're in a covered area. Check your plan details to make sure the country or region you're in is covered. If you're inside an airport building or underground, try moving to an area with better signal.

5. Wait a few minutes. In some cases, the eSIM profile needs a brief moment to register with the local network after first activation. Give it 2-5 minutes.

If none of these steps work, reach out to our support team at onlyesim.com and we'll help you get connected.

Common questions

I activated my eSIM but my phone says 'No Service.' What should I do?

First, make sure Data Roaming is turned on (this is the most common fix). Then try toggling Airplane Mode on, wait 10 seconds, and toggle it off. If that doesn't work, restart your phone completely. If you still see 'No Service' after restarting, check that you're in a coverage area for your plan's destination country.

Will activating the eSIM affect my regular phone number and calls?

On a compatible dual-SIM phone, you can keep your regular SIM enabled for calls and texts while selecting your travel eSIM for data. Check your phone's line settings and your home carrier's roaming charges. Do not assume a phone number, carrier calls, or SMS are included with your travel plan; confirm its terms before buying.

Does my plan start counting from the moment I activate, or from the moment I use data?

It depends on the plan. Some plans have 'instant activation,' meaning validity starts the moment the eSIM profile is downloaded or installed. Other plans have 'activation upon arrival,' meaning validity starts when the eSIM first connects to a cell tower in the destination country. Check your specific plan details on your order page to see which type you have.