Traveling abroad with a Polish SIM card often raises concerns about unexpectedly high phone bills. Within the EU/EEA, roaming is generally covered by the Roam Like at Home rules, but outside this area mobile data can become very expensive. A practical solution is to use your Polish SIM together with a travel eSIM in Dual SIM mode: your Polish number remains active for calls and SMS, while mobile data is handled by the eSIM. Below is a step-by-step guide for iPhone and Android.

TL;DR Roaming in the EU/EEA is covered by RLAH rules, while outside the EU data charges can be much higher. The safest setup is to use the eSIM for mobile data and keep the Polish physical SIM only for calls and SMS. To avoid unexpected charges, turn off data roaming on the Polish SIM, set the eSIM as the default data line, and disable automatic data switching. This lets you keep your Polish number while using a separate travel data package abroad.

Dual SIM abroad – how it works and why eSIM is a practical option

Dual SIM abroad usually works through Dual SIM Dual Standby (DSDS). This means two SIM profiles can remain active at the same time, but mobile data is normally used through only one of them at any given moment.

In practice, your Polish SIM can remain active for calls, SMS messages, and verification codes, while the eSIM handles all mobile data.

This setup helps you control roaming costs because your internet traffic does not need to pass through your Polish SIM. Within the EU/EEA, roaming rules make domestic plans relatively convenient, but outside the EU prices can increase significantly depending on your operator.

A XOXO WiFi eSIM is designed primarily for mobile data, which means you can keep your Polish number active while using the eSIM for internet access abroad.

What to prepare before your trip

Before setting up Dual SIM, first check whether your device supports eSIM and whether it is unlocked.

Typical compatible devices include:

• iPhone XS/XR and newer,
• Samsung Galaxy S20 series and newer selected models,
• Google Pixel models with eSIM support,
• selected Xiaomi devices,
• selected Huawei devices.

Your phone should also be SIM-lock free.

One quick way to check eSIM support is to dial *#06#. If your phone displays an EID, it usually means the device supports eSIM.

Buying and installing an eSIM

Before departure:

• buy the eSIM online,
• install it while you still have stable Wi-Fi,
• keep the QR code or installation details available,
• check when the validity period begins,
• confirm whether data roaming needs to be enabled for the eSIM.

Many travel eSIMs activate only when they first connect to a supported network at the destination.

How to configure Dual SIM on iPhone

The goal is simple: your iPhone should use the eSIM for data and your Polish SIM only for calls and SMS.

Step 1. Install the eSIM

Go to:

Settings → Cellular / Mobile Data → Add eSIM

Scan the QR code or enter the eSIM details manually.

Step 2. Set the eSIM as your mobile data line

Go to:

Settings → Cellular / Mobile Data → Cellular Data

Select your travel eSIM.

Step 3. Turn off “Allow Cellular Data Switching”

This is one of the most important settings.

If this option is enabled, the iPhone may switch data traffic to your Polish SIM when the eSIM connection is weak.

Turn it off before traveling.

Step 4. Turn off data roaming on your Polish SIM

Go to:

Settings → Cellular / Mobile Data → [Polish SIM] → Data Roaming

Turn Data Roaming OFF.

Step 5. Turn on data roaming for the eSIM

Go to:

Settings → Cellular / Mobile Data → [eSIM] → Data Roaming

Turn it ON if required by your travel eSIM provider.

This may sound counterintuitive, but many travel eSIMs connect through roaming agreements with local networks. The important point is that the data is billed against your travel eSIM package, not your Polish operator.

How to configure Dual SIM on Android

The exact menu names vary between Samsung, Google Pixel, Xiaomi, and other manufacturers, but the principle is the same.

Step 1. Install the eSIM

Add the eSIM using the QR code in your phone’s mobile network settings.

Step 2. Open SIM settings

Examples:

Samsung:
Settings → Connections → SIM Manager

Google Pixel:
Settings → Network & Internet → SIMs

Xiaomi:
Settings → SIM cards & mobile networks

Step 3. Set the eSIM as the default data SIM

Choose the travel eSIM for Mobile Data.

Step 4. Disable automatic data switching

Some Android phones allow the device to switch to another SIM automatically if the preferred data SIM loses signal.

Turn this option off.

Step 5. Disable data roaming on your Polish SIM

Open the settings for your Polish SIM and make sure:

Data Roaming → OFF

Step 6. Enable data roaming for the eSIM

Open the eSIM settings and turn:

Data Roaming → ON

if required by the eSIM provider.

Checklist – how to make sure your settings are correct

Before departure

• Set the eSIM as the default mobile data SIM.
• Turn off data roaming on your Polish SIM.
• Turn off automatic cellular data switching.
• Confirm that the eSIM profile is installed correctly.
• Check whether the eSIM requires data roaming to be enabled.

After landing

• Turn on the travel eSIM.
• Make sure the eSIM connects to a local network.
• Check that mobile data is still assigned to the eSIM.
• Confirm that data roaming remains disabled on your Polish SIM.

Common Dual SIM mistakes and how to fix them

The most common mistake is leaving automatic data switching enabled. Even if you have correctly selected the eSIM for data, the phone may switch to the Polish SIM when the eSIM signal becomes weaker.

Can I still receive calls and SMS on my Polish number?

Yes.

This is one of the main advantages of Dual SIM. Your Polish SIM can stay active for:

• incoming calls,
• SMS messages,
• banking verification codes,
• account recovery messages,
• your existing WhatsApp number.

At the same time, your eSIM can be used exclusively for mobile data.

However, calls and SMS made through your Polish SIM may still be subject to roaming charges outside the EU/EEA, so check your operator’s rates.

Does WhatsApp keep my Polish number?

Yes.

Installing a travel eSIM does not automatically change your WhatsApp number. WhatsApp remains linked to the number used when the account was set up.

You can therefore keep your Polish SIM active while using the eSIM for internet access.

When is Dual SIM with eSIM the best option?

Dual SIM is particularly useful when:

• you want to keep your Polish phone number,
• you need mobile data abroad,
• you want to avoid using your Polish SIM for data roaming,
• you travel outside the EU,
• you want to use WhatsApp and banking SMS normally,
• you do not want to replace your main SIM card.

For many solo travelers, this is one of the simplest ways to combine convenience with cost control.

When should you choose a mobile router instead?

A portable router may be more practical if:

• your phone does not support eSIM,
• several people need internet access,
• you want to connect a phone, tablet, and laptop,
• you need a dedicated Wi-Fi hotspot,
• you do not want to use your phone as a hotspot all day.

A portable XOXO WiFi router can connect multiple devices and may be a better choice for families, groups, or remote workers.

Is eSIM safer than public Wi-Fi?

A mobile data connection through an eSIM is generally a better option than relying on open public Wi-Fi networks.

Public hotspots in airports, hotels, and cafés may be shared by many users and can be less predictable in terms of security and performance.

For work accounts, banking, and other sensitive services, using your own mobile connection is usually preferable. If your company requires a VPN, you should still use it while traveling.

Dual SIM abroad – final recommendation

If you want to keep your Polish number while avoiding data roaming charges on that SIM, the setup is straightforward:

• keep your Polish SIM active,
• use the eSIM for mobile data,
• turn off data roaming on the Polish SIM,
• turn on data roaming for the eSIM if required,
• disable automatic data switching.

This configuration gives you the convenience of your regular number and the predictability of a separate travel data package.

For individual travelers, Dual SIM with a travel eSIM is usually the simplest option. For families, groups, or users with several devices, a portable router may be more practical.