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This section explains the network settings relevant to using an eSIM while travelling — from the APN configuration some devices need entered manually, to choosing a network mode, through to why a device sometimes shows an unfamiliar network name. What is written here focuses on settings and network behaviour, not the installation or activation steps, which live in other categories.

If the symptom is that data does not work at all despite activation, check the activation category first to confirm every step has genuinely been completed. If activation was done correctly but there is still a problem with speed or a weak signal, the data-speed category answers that more directly.

What APN settings are and how much they matter

APN stands for Access Point Name — a value that tells the device which channel to use when connecting to the data network. Most devices set this automatically the moment a profile is installed and connects successfully, though some models or situations may require entering it manually.

The correct APN value for your plan, if one is needed, is stated in your order confirmation email. We do not recommend guessing or copying an APN value from a different plan, since each underlying network uses its own value — entering the wrong one can prevent the device from connecting to the network at all.

Which network mode to choose

The network mode menu usually offers several choices, such as automatic selection or a fixed network type. Generally it is best set to automatic, or to the broadest option the device supports, letting the device choose whichever network is best in that area itself.

Locking the network mode to a fixed, older-generation type can result in slower connections or no signal at all in areas that generation does not cover. Without a specific reason, there is no need to change it away from the automatic setting it came with.

Why the network name shown is unfamiliar

Turning mobile data on or off while roaming

The device's overall mobile data switch must stay on for the eSIM profile to work at all, separate from that specific profile's own data roaming switch, which is explained in the activation category. If the overall mobile data switch is off, the device will not connect to the internet over any mobile network, regardless of which SIM is involved.

If the device holds both the original main SIM and the eSIM profile at once, check whether the eSIM profile is already set as the primary data route, since if the device is still using the main SIM for data, unintended roaming charges from that main SIM could result.

Using a VPN alongside an eSIM

Using a VPN while connected through an eSIM works just as it would over any other mobile connection, though a VPN can reduce speed somewhat since data passes through an additional intermediary server, and some countries carry legal restrictions on VPN use, which is something the traveller needs to check for themselves against the destination country's own rules.

Can Wi-Fi Calling or internet-calling apps be used?

Since most travel plans are data-only with no local voice number, making or receiving calls usually relies on internet-calling apps, such as popular messaging apps that support calling, which use the eSIM profile's data normally, as long as an internet connection is present.

The operating system's own Wi-Fi Calling feature is usually tied to your original main SIM, not the newly installed eSIM profile. If you want to use that feature, check with your main SIM's operator whether it supports this and have it switched on before travelling.

• Let the device set the APN automatically first
• Set the network mode to automatic unless there is a specific reason not to
• Confirm the eSIM profile is set as the primary data route
• Switch off data roaming for the original main SIM before travelling
• Do not be alarmed if the network name shown is unfamiliar

Check data-speed issues

Read the profile activation steps

Selecting a network manually when it is genuinely necessary

The network settings menu usually offers an option to search for and pick a network manually instead of automatic mode, which is not normally needed, since the device already selects the best network in the area on its own. This option is useful only when the device gets stuck on an unusually weak network despite another one being present in the same area.

Selecting manually means opening the list of every network the device has detected, then choosing a different partner network from that list instead. It is worth setting it back to automatic afterwards, since locking onto one network permanently can mean missing a better one after moving to a different area.

Status-bar icons worth recognising

The status bar shows several icons while roaming, some of which may look unfamiliar compared with being at home. The table below explains the general meaning without referring to any one manufacturer's specific icon design, since the exact appearance can differ by operating system and version.

Resetting network settings safely

A network settings reset menu exists on most devices, though its exact location and name differ by manufacturer and OS version. This reset can fix an oddly stuck network setting in some cases, without removing an already-installed eSIM profile from the device.

Why connecting to Wi-Fi can make mobile data look broken

Most devices automatically prefer Wi-Fi over mobile data the moment a Wi-Fi connection succeeds, which can make an eSIM profile look broken when it is really just not being used at that moment because Wi-Fi is available instead.

To test whether the eSIM profile genuinely works, switch Wi-Fi off temporarily and try opening a webpage using only mobile data. If it still loads normally, the profile is genuinely connected and working.

Per-app permission to use mobile data

Some operating system versions carry a separate menu that allows or blocks a specific app from using mobile data at all, apart from the profile's main data-roaming switch. If an app you need still does not work despite the network otherwise connecting normally, this menu is worth checking too.

The location of this menu differs by manufacturer and OS version just like other menus, so searching for terms such as data usage or network access permission within the settings search box is the way to find its real location on your own device.

The network remembers a previous connection

When returning to the same area or country again within a short time, the device often reconnects to the same network it used before more quickly than the first time, since some connection information from before was retained. That said, this behaviour is not guaranteed, especially if the device stayed off for a long while or the profile was deleted and reinstalled.

If a connection is unusually slow despite the same network having been used before, restarting the device or toggling airplane mode remains the most direct fix, since it forces a fresh network search from scratch rather than relying on old information that may no longer match current conditions.

Still cannot get it configured? Contact the team

If adjusting the network mode, checking the APN and resetting network settings still leaves it unable to connect, contact the team via LINE at https://lin.ee/skDPoNx (ID @esimonline) or by email at esimonline.asia@gmail.com, stating the device model, operating system, and everything already tried.

A screenshot of the settings menu currently being attempted also helps a great deal, since the team can see the actual options on your device without having to guess what that menu looks like on the exact model and version you are using.

If a problem only shows up in certain areas of the same country, name the city or district where it happened rather than just the country, since network behaviour can differ from area to area even within one country. Being specific helps the team check and give more targeted advice.

• Let the device choose networks automatically unless stuck on an unusually weak one
• Unfamiliar status icons while roaming are usually normal
• A network settings reset does not remove the eSIM profile, but does clear saved Wi-Fi passwords
• Switch Wi-Fi off temporarily to test whether mobile data genuinely works
• Check the per-app data permission menu if one specific app in particular fails to work
• Contact the team via LINE or email with detail on what has already been tried