---
title: "Two lines. One deliberate data choice. | DualLine"
description: "Understand travel eSIM data roaming, your home line and automatic data switching. Review settings before departure and after returning home."
canonical: "https://dualline.co/esim/guides/data-roaming"
---

# Two lines. One deliberate data choice.

Data roaming is a setting for a particular line. A travel eSIM may need roaming enabled under its package instructions while your home line has data roaming disabled. Check each line separately; keeping a home number active can still incur call or message charges.

## Separate the three decisions

Which line supplies mobile data? Which number do you use for carrier calls and messages? Which line is allowed to roam? Write down your intended setup before changing switches.

On a compatible dual-SIM phone, the travel eSIM can provide data while the home line remains available, subject to device, carrier and package conditions. Review automatic data switching because it can change which line carries data.

## Read the package, then set the phone

Some travel packages use roaming network access. Turning roaming off everywhere can prevent a correctly installed travel eSIM from connecting. Follow the instructions for the travel line and review the home line’s settings separately.

Check the home carrier’s charges before receiving calls, sending SMS or using voicemail abroad. A travel data package does not control another carrier’s bill.

- [Buy a travel eSIM](https://dualline.co/buy-esim)

## Before departure and after return

Before leaving, record your usual default line and download essential journey information over a trusted connection. This gives you a practical fallback if coverage is temporarily unavailable.

On return, deliberately restore your preferred data and call settings. Keep any travel profile only as appropriate for its package terms; do not assume deletion cancels a purchase or that reinstallation will be possible.

## Your take-away checklist

- Choose the intended mobile data line.
- Check roaming separately on each line.
- Review automatic data switching.
- Check home-carrier call and SMS charges.
- Restore your preferred settings after the trip.

## Sources and support

Use the manufacturer’s current instructions for your device and the selected package’s details for its terms.

- [Apple — Travel internationally with eSIM](https://support.apple.com/en-us/118227)
- [Apple — Using Dual SIM](https://support.apple.com/en-us/109317)

[Contact DualLine support](https://dualline.co/support)  ·  [Refund and cancellation terms](https://dualline.co/refund-cancellation)

## Your next step

[### Is your phone ready for a travel eSIM?

Check exact model, sales region, carrier lock and dual-SIM needs before choosing a travel eSIM. A practical compatibility checklist for iPhone and Android.

 Read guide](https://dualline.co/esim/guides/device-compatibility) [### Install your travel eSIM with a clear plan.

Prepare for eSIM installation on iPhone or Android: delivery details, QR or manual setup, activation timing and choosing the correct data line.

 Read guide](https://dualline.co/esim/guides/installation) [### Your eSIM is not connecting. What next?

Distinguish eSIM delivery, installation, network and data-usage problems. Follow a focused troubleshooting checklist and prepare useful support details.

 Read guide](https://dualline.co/esim/guides/not-connecting) [### What is an eSIM, and which plan do you need?

Understand eSIM, travel data, phone numbers and setup. Choose between data-only and calls-and-texts plans without changing your everyday number.

 Read guide](https://dualline.co/esim/guides/what-is-esim)