Yes, you can use your regular SIM and a travel eSIM together if your smartphone supports dual-SIM functionality.

This is one of the biggest advantages of using a travel eSIM. You don't necessarily have to remove your existing physical SIM when travelling internationally.

Instead, you can keep your regular SIM in your phone and add a travel eSIM such as eSIMLLY for mobile data.

A common international travel setup looks like this:

Regular SIM → Your existing phone number, calls and SMS

eSIMLLY → Travel mobile data

This allows you to stay connected to your existing number while using a separate travel data plan abroad.

eSIMLLY provides travel eSIM coverage across 160+ countries, with different data allowances and validity periods depending on the destination.

Explore eSIMLLY travel eSIM plans

What Does Using a Regular SIM and eSIM Together Mean?

A smartphone that supports dual-SIM functionality can store and use more than one cellular line.

One line can be your existing physical SIM, while another can be your travel eSIM.

For example:

SIM 1: Your regular SIM

Used for:

• Your existing phone number

• Calls

• SMS

• Account verification

• Your normal mobile service

SIM 2: eSIMLLY

Used primarily for:

• Mobile data

• Google Maps

• WhatsApp

• Email

• Social media

• Travel applications

• Web browsing

The exact capabilities depend on your smartphone, carrier, and eSIM plan.

How Does Dual SIM Work With a Travel eSIM?

When you install eSIMLLY on a compatible smartphone, your phone can display both cellular lines.

You can usually give each line a name so that you can identify them easily.

For example:

Primary → Personal SIM

Travel → eSIMLLY

You can then select which line should be used for mobile data.

When travelling, you can choose the eSIMLLY Travel line for mobile data while keeping your regular SIM installed.

Why Use Your Regular SIM and eSIMLLY Together?

There are several reasons travelers choose this setup.

Keep Your Existing Number

You don't have to replace your primary SIM just because you're travelling.

Continue Using Your Existing Services

Your regular number can remain available for services supported by your carrier.

Use a Separate Travel Data Plan

eSIMLLY can provide mobile data for your trip.

Avoid Physical SIM Swapping

You don't have to remove your SIM card and store it somewhere safe.

Use WhatsApp With Your Existing Number

Your WhatsApp account can continue to use your existing number while your internet connection comes from eSIMLLY.

Switch Data Lines Easily

On compatible devices, you can change which SIM is used for mobile data through your phone's settings.

Can Your Regular SIM Stay Active While Using eSIMLLY?

Yes, on a compatible dual-SIM device.

Your regular SIM can remain installed while your eSIMLLY travel plan provides mobile data.

A typical setup can look like:

The exact functionality varies by device and plan.

How to Set Up Your Regular SIM and eSIMLLY Together

The process is straightforward.

Step 1: Check Your Phone

First, make sure your smartphone supports eSIM and dual-SIM functionality.

eSIMLLY supports compatible devices from manufacturers such as Apple, Samsung, and Google Pixel, among others.

Check your device compatibility with eSIMLLY

Step 2: Purchase Your eSIMLLY Plan

Select the destination you are travelling to and choose a suitable data plan.

eSIMLLY provides coverage across 160+ countries.

You can choose from different data allowances and validity periods depending on your destination.

Step 3: Install the eSIM

Install the eSIM using the activation information provided with your eSIMLLY purchase.

You can typically scan the QR code or use the provided manual activation information.

View the eSIMLLY installation guide

Step 4: Label Your Lines

After installation, give the lines recognizable names.

For example:

Primary SIM → Home

eSIMLLY → Travel

This makes it easier to select the correct line when configuring your phone.

Step 5: Select eSIMLLY for Mobile Data

Before or after arriving at your destination, go to your cellular/mobile network settings.

Select the eSIMLLY line as your mobile data line.

This tells your phone to use eSIMLLY for internet access.

Step 6: Control Your Regular SIM's Data

If you're travelling internationally, be careful with mobile data on your regular SIM.

If your home carrier charges international roaming fees, you generally want to prevent your regular SIM from accidentally using roaming data.

Your exact settings depend on your phone.

Should You Turn Off Your Regular SIM?

Not necessarily.

You can often keep your regular SIM active while using eSIMLLY for mobile data.

Whether you should leave it fully active depends on what you need from your primary SIM and what your home carrier charges for roaming.

For example, if you need your regular number for certain calls or SMS, you may want to keep the line active.

However, you should review your carrier's international roaming charges before travelling.

How Do You Avoid Roaming Charges While Using Both SIMs?

This is one of the most important parts of setting up a travel eSIM.

If your regular SIM is capable of using mobile data while abroad, your phone could potentially use your home carrier's roaming data if the settings aren't configured correctly.

To avoid unnecessary roaming data usage:

Set eSIMLLY as your mobile-data line

Make sure your travel eSIM is selected for mobile data.

Disable data roaming on your regular SIM

If appropriate for your carrier and setup, turn off data roaming on your primary line.

Avoid automatic data switching

Some phones have features that can automatically switch mobile-data lines when the preferred line has poor connectivity.

If you're trying to prevent roaming charges, check whether this feature is enabled.

Monitor your mobile-data usage

Check which SIM is being used for data.

Check your home carrier's roaming terms

Some carriers include international roaming in their plans, while others charge additional fees.

Your carrier's rules determine what happens when your regular SIM connects abroad.

Can You Receive Calls on Your Regular SIM While Using eSIMLLY?

Potentially, yes.

If your regular SIM remains active and your home carrier supports international roaming in your destination, you may be able to receive calls on your existing number.

However, roaming charges may apply depending on your carrier and plan.

Using eSIMLLY for data does not automatically eliminate charges associated with calls or SMS on your regular SIM.

Always check your carrier's international roaming policy before travelling.

Can You Receive SMS on Your Regular Number?

Potentially, yes.

If your regular SIM remains active and your carrier supports international roaming, SMS can continue to work while abroad.

This can be particularly useful for:

• Login verification

• One-time passwords

• Banking alerts

• Account security

• Important messages

However, whether receiving SMS is free or charged depends on your home carrier's roaming policy.

Can You Make Calls Using Your Regular SIM?

Potentially, yes, if your regular carrier provides roaming service in your destination.

But traditional cellular calls while roaming can be expensive depending on your carrier.

If your goal is to reduce roaming costs, consider using internet-based calling services such as WhatsApp when possible.

Your eSIMLLY mobile data can provide the internet connection required for those applications.

Can You Use WhatsApp With Your Regular SIM and eSIMLLY?

Yes.

You can keep your existing WhatsApp account associated with your normal phone number while using eSIMLLY for mobile data.

For example:

WhatsApp account: Existing number

Regular SIM: Existing number

eSIMLLY: Travel data

WhatsApp can use the eSIMLLY mobile-data connection for:

• Messages

• Voice calls

• Video calls

• Photos

• Videos

• Location sharing

This is one of the most useful combinations for international travel.

Can You Use Google Maps With Your Regular SIM and eSIMLLY?

Yes.

If eSIMLLY is selected as your mobile-data line, Google Maps can use the eSIMLLY connection.

You don't need to change your Google account or phone number.

You simply need an active internet connection.

For example:

Regular SIM → Existing number

eSIMLLY → Mobile data

Google Maps → Uses eSIMLLY data

This setup is particularly convenient when navigating a new city.

Can You Receive OTPs While Using eSIMLLY?

If your regular SIM remains active and your carrier supports the necessary roaming service, you may continue receiving SMS messages, including certain verification messages.

This can be useful when accessing:

• Banking services

• Email accounts

• Social media accounts

• Travel bookings

• Security systems

However, SMS delivery and charges depend on your carrier and roaming configuration.

The eSIMLLY travel plan itself should not be assumed to provide OTP SMS to your existing number.

Can You Use iMessage With Your Regular SIM and eSIMLLY?

On compatible Apple devices, iMessage can use an internet connection.

If eSIMLLY provides mobile data, internet-based iMessage functions can use that connection.

Your exact iMessage configuration depends on your iPhone and Apple account settings.

If your existing number is associated with iMessage, changing your mobile-data line does not necessarily mean you need to change your iMessage identity.

Can You Use FaceTime With eSIMLLY?

Yes.

FaceTime uses an internet connection, so it can use mobile data from eSIMLLY on compatible Apple devices.

This allows you to make internet-based voice or video calls while travelling.

Remember that video calls consume more data than simple text messaging, so choose your eSIMLLY data allowance accordingly.

Can You Use Your Regular SIM for Calls and eSIMLLY for Data?

Yes, this is one of the most common dual-SIM travel configurations.

Your setup can look like:

Regular SIM

• Existing phone number

• Calls

• SMS

eSIMLLY

• Mobile data

• WhatsApp

• Google Maps

• Email

• Social media

• Travel apps

This gives you the convenience of keeping your existing number while using a dedicated travel data plan.

Does Using Two SIMs Drain Your Battery Faster?

Using dual-SIM functionality can affect battery consumption because the phone may maintain connections to multiple cellular lines.

However, the actual impact depends on:

• Phone model

• Network strength

• Network technology

• Whether both lines are active

• How frequently the phone searches for networks

• Your overall usage

If battery life is important during travel, carrying a power bank can still be useful.

Can You Switch Between the Two SIMs?

Yes, compatible dual-SIM smartphones generally allow you to manage your lines through the phone's settings.

You can choose:

• Which SIM handles mobile data

• Which SIM is used for calls

• Which SIM is preferred for certain services

The exact interface differs between iPhone, Samsung, Google Pixel, and other devices.

What Happens if eSIMLLY Runs Out of Data?

If your eSIMLLY data allowance is exhausted, your mobile data service may stop or become unavailable depending on the plan.

You may then be able to purchase additional data or another available plan, depending on the destination and service.

Alternatively, your phone could potentially use your regular SIM for mobile data if you have enabled that option.

However, be careful.

If your regular SIM is subject to international roaming charges, switching mobile data back to it could result in additional costs.

Can You Use eSIMLLY and Your Regular SIM in Different Countries?

Yes, provided both services are supported in the relevant locations.

For example, if you're travelling through Europe, you can use your eSIMLLY regional or destination plan where supported while keeping your home SIM installed.

The exact coverage depends on the eSIMLLY plan and your home carrier's roaming availability.

Example: Using Your Regular SIM + eSIMLLY in Japan

Suppose you're travelling from India to Japan.

You could configure your phone as:

Indian SIM

→ Keep your existing number

→ Receive supported SMS

→ Maintain your normal SIM profile

eSIMLLY Japan eSIM

→ Mobile data

→ Google Maps

→ WhatsApp

→ Translation apps

→ Travel applications

eSIMLLY offers different Japan data plans, allowing you to choose according to your expected usage and trip duration.

Check eSIMLLY Japan plans

Example: Using Your Regular SIM + eSIMLLY in Singapore

If you're travelling to Singapore, you can similarly keep your regular SIM installed while using an eSIMLLY Singapore plan for travel data.

This can allow you to:

• Keep your existing number

• Use WhatsApp

• Navigate with Google Maps

• Check emails

• Use ride-hailing applications

• Browse the internet

Check eSIMLLY Singapore plans

Example: Using Your Regular SIM + eSIMLLY in France

A France eSIMLLY plan can be used for travel data while your regular SIM remains installed on a compatible dual-SIM phone.

You can use the eSIMLLY connection for:

• Google Maps

• WhatsApp

• Travel apps

• Social media

• Email

• Web browsing

Check eSIMLLY France plans

Which Phones Can Use a Physical SIM and eSIM Together?

Many modern smartphones support combinations of physical SIM and eSIM.

Compatible devices can include models from:

• Apple

• Samsung

• Google Pixel

• Other manufacturers

However, support varies by exact model and region.

Some devices may support:

1 physical SIM + 1 eSIM

while others may support different combinations.

Some newer phones may also be eSIM-only depending on the market.

Always check your exact device before travelling.

Check eSIMLLY device compatibility

How to Set Up Your Phone Before Leaving

For the smoothest experience, configure your phone before you travel.

Before departure:

1. Confirm that your phone supports eSIM.

2. Make sure your phone is compatible/unlocked where required.

3. Purchase your eSIMLLY plan.

4. Install the eSIM.

5. Label the eSIM as "Travel" or "eSIMLLY."

6. Keep your regular SIM installed.

7. Select eSIMLLY for mobile data when appropriate.

8. Review data-roaming settings for your primary SIM.

9. Consider disabling automatic mobile-data switching.

10. Test your eSIM setup if appropriate.

Follow the eSIMLLY installation guide

What Should Your Travel SIM Settings Look Like?

A typical configuration could be:

SIM 1 — Regular SIM

Calls: On if needed

SMS: On if needed

Mobile data: Off or not selected for travel data

Data roaming: Configured according to your carrier and travel requirements

SIM 2 — eSIMLLY

Mobile data: On

Data roaming: Follow eSIMLLY plan instructions

Calls/SMS: Depends on the specific plan

Your phone's exact settings will vary, so always follow the instructions for your particular device and eSIMLLY plan.

Should You Turn Off Data Roaming on Your Regular SIM?

If you want to avoid your primary carrier's roaming data charges, you should review the data-roaming setting for that SIM.

The correct configuration depends on your carrier and phone.

The key idea is:

eSIMLLY = Travel mobile data

Regular SIM = Keep available for the services you need

Make sure your phone does not automatically switch mobile data back to your primary SIM.

Is It Better to Remove Your Regular SIM?

Not necessarily.

One of the biggest advantages of using an eSIM is that you can keep your physical SIM in your phone.

You don't have to:

• Remove the SIM tray

• Store your SIM somewhere

• Risk losing the SIM

• Insert it again after returning home

Instead, you can simply manage your travel eSIM through your phone's settings.

Why eSIMLLY Is Useful With Your Existing SIM

eSIMLLY is designed to provide travel connectivity without requiring you to replace your primary SIM.

With coverage across 160+ countries, you can choose a travel plan based on your destination.

Depending on the destination, eSIMLLY offers different:

• Data allowances

• Validity periods

• Destination plans

• Regional plans

• Connectivity options

This makes it possible to keep your normal SIM while adding a dedicated travel-data connection.

Frequently Asked Questions

Can I use my regular SIM and travel eSIM together?

Yes, if your smartphone supports dual-SIM functionality. You can keep your regular SIM installed and use eSIMLLY as your travel-data line.

Can I use my regular SIM for calls and eSIMLLY for data?

Yes. This is a common dual-SIM travel configuration on compatible devices.

Can I keep my existing phone number?

Yes. Your regular SIM can remain associated with your existing phone number.

Can I use WhatsApp with my regular number and eSIMLLY data?

Yes. Your WhatsApp account can remain associated with your existing number while WhatsApp uses eSIMLLY's mobile data.

Can I receive SMS on my normal number while using eSIMLLY?

Potentially, if your regular SIM remains active and your carrier supports roaming in your destination. Carrier terms and charges may apply.

Can I receive OTPs while travelling?

You may be able to receive OTPs through your regular SIM if SMS roaming is supported by your carrier. Check your carrier's international roaming terms.

Will my regular SIM automatically incur roaming charges?

It can, depending on your carrier and which services are used while abroad. Review your carrier's roaming policy and configure your phone carefully.

Can I use Google Maps with eSIMLLY?

Yes. Google Maps can use eSIMLLY mobile data on a compatible phone.

Can I use WhatsApp calls with eSIMLLY?

Yes. WhatsApp voice and video calls can use eSIMLLY mobile data where the service is available.

What happens if I run out of eSIMLLY data?

Depending on the plan, you may be able to purchase additional data or another plan. You can also use Wi-Fi where available.

How many countries does eSIMLLY cover?

eSIMLLY currently provides travel eSIM coverage across 160+ countries.

Do I need to remove my physical SIM before installing eSIMLLY?

No. On compatible devices, you can keep your physical SIM installed and add eSIMLLY as another cellular line.

Final Thoughts

Yes, you can use your regular SIM and a travel eSIM together.

For many international travelers, this is one of the most convenient ways to configure a smartphone.

A practical setup is:

Regular SIM → Your existing number, calls and SMS

eSIMLLY → Travel mobile data

This lets you keep your existing number while using a dedicated eSIMLLY data plan for:

• Google Maps

• WhatsApp

• Email

• Social media

• Translation apps

• Ride-hailing

• Travel bookings

• Web browsing

The most important thing is to configure your phone correctly so that your primary SIM does not unintentionally use expensive roaming data.

With eSIMLLY coverage across 160+ countries, different data allowances, and different validity periods depending on the destination, you can add a travel eSIM without having to remove your everyday SIM.

Keep your regular SIM. Add eSIMLLY. Use eSIMLLY for travel data. Stay connected throughout your trip.

Explore eSIMLLY travel eSIM plans