> ## Documentation Index
> Fetch the complete documentation index at: https://support.onroamly.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Data roaming: why it must be on for your Roamly line

> Roaming costs nothing extra on a Roamly eSIM. It's the switch that lets your phone use the local network. Leave it off on your home SIM only.

"Roaming" is the word that stops people from getting online. With a Roamly eSIM it's just a switch, and it needs to be on.

## No, it won't cost you extra

Your plan price is all you ever pay. A travel eSIM works *by* roaming: it's a SIM from one network that's allowed to use the networks at your destination, and Data Roaming is simply the setting that lets your phone do that. Leaving it off doesn't save money; it keeps you offline.

The setting that *does* cost money is Data Roaming on your **home SIM**. Keep that one off, and your home carrier can't charge you a cent.

## Turn it on for the Roamly line

<Tabs>
  <Tab title="iPhone">
    <Steps>
      <Step title="Open Settings → Mobile">
        Older iPhones say *Mobile Service* or *Mobile Data*; some regions say *Cellular*.
      </Step>

      <Step title="Tap your Roamly line under SIMs">
        It's the one you labelled when installing, often *Travel*; iOS may add the network name after it.

        <Frame>
          <img src="https://mintcdn.com/roamly-support/tvts_C2A1tz3UsYQ/images/troubleshooting/data-roaming/iphone-2-tap-your-roamly-line.webp?fit=max&auto=format&n=tvts_C2A1tz3UsYQ&q=85&s=283a46a26db916c978e63ebde572bb73" alt="Settings → Mobile with the Roamly line highlighted under SIMs" width="2400" height="1254" data-path="images/troubleshooting/data-roaming/iphone-2-tap-your-roamly-line.webp" />
        </Frame>
      </Step>

      <Step title="Turn on Data Roaming">
        Make sure **Turn on this Line** is on as well.

        <Frame>
          <img src="https://mintcdn.com/roamly-support/tvts_C2A1tz3UsYQ/images/troubleshooting/data-roaming/iphone-3-data-roaming-on.webp?fit=max&auto=format&n=tvts_C2A1tz3UsYQ&q=85&s=7ad1a03056c371a78efcee9b308e83d2" alt="The Roamly line's settings with Data Roaming switched on" width="2400" height="1254" data-path="images/troubleshooting/data-roaming/iphone-3-data-roaming-on.webp" />
        </Frame>
      </Step>

      <Step title="Check the data line">
        Back in Mobile, tap **Mobile Data** at the top and choose the Roamly line. Leave **Allow Mobile Data Switching** off, so the phone can't quietly fall back to your normal SIM.

        <Frame>
          <img src="https://mintcdn.com/roamly-support/tvts_C2A1tz3UsYQ/images/troubleshooting/data-roaming/iphone-4-select-roamly-for-mobile-data.webp?fit=max&auto=format&n=tvts_C2A1tz3UsYQ&q=85&s=0b40b73f9e48a36ca1a552e13913ab9d" alt="The Mobile Data row, then the picker with the Roamly line selected and Allow Mobile Data Switching off" width="2400" height="1254" data-path="images/troubleshooting/data-roaming/iphone-4-select-roamly-for-mobile-data.webp" />
        </Frame>
      </Step>
    </Steps>
  </Tab>

  <Tab title="Android">
    <Steps>
      <Step title="Open Settings → Network & internet → SIMs">
        Samsung: Settings → Connections → SIM manager.
      </Step>

      <Step title="Tap your Roamly SIM">
        Make sure **Use this SIM** is on.
      </Step>

      <Step title="Turn on Roaming">
        Samsung keeps this at Settings → Connections → Mobile networks → **Data roaming**.
      </Step>

      <Step title="Set Roamly as the mobile data SIM">
        On the SIMs screen, tap **Mobile data** and choose Roamly.
      </Step>
    </Steps>
  </Tab>
</Tabs>

## And off for your home SIM

Same screens, other SIM: turn its roaming off. If you'd rather not think about it, switch the home SIM off for the trip; see [I'm being charged roaming by my home carrier](/troubleshooting/at-your-destination/home-carrier-roaming-charges).

## Still not connecting?

Flick Airplane Mode on and off to make the phone re-register, then work through [Just landed and no data? Start here](/troubleshooting/at-your-destination/no-data-start-here).