Can You Keep Your Australian Number With a Bali eSIM?

If you're travelling from Australia to Bali, you might be wondering whether using a travel eSIM means giving up your Australian mobile number. The short answer is no — on a compatible phone, you can generally keep your Australian SIM installed while using a Bali eSIM for mobile data.

This guide explains how that works, what to check before you fly, and what to watch out for when it comes to calls, SMS and your carrier's roaming terms.

How does using two SIMs at once work?

Many modern phones support dual SIM functionality, which means they can have two SIM profiles active at the same time — one physical SIM and one eSIM, or in some cases two eSIMs.

When you're travelling in Bali, the typical setup is:

• Australian SIM — your normal Australian mobile service and phone number, installed as usual.
• Bali travel eSIM — a data-only eSIM that provides mobile data while you're travelling.

On a supported device, both can be installed simultaneously. Your phone manages which one is used for what — for example, you can set the Bali eSIM as your mobile data line while keeping the Australian SIM available for calls and SMS.

Exact behaviour depends on your device and carrier, so it's worth checking your phone's dual SIM settings before you travel. You can check whether your phone supports eSIM using our compatibility checker.

Will my Australian phone number change?

No. Installing a Roamza travel eSIM does not transfer or replace your Australian mobile number.

Your Australian number remains associated with your Australian SIM and carrier. Roamza eSIMs are data-only — they provide mobile data, not a new phone number.

Nothing about your Australian mobile service changes when you install a travel eSIM. You're simply adding a second data connection that your phone can use while you're overseas.

Can I receive SMS on my Australian number in Bali?

In many cases, yes — your Australian SIM can remain available for SMS while you're in Bali. But it's not automatic, and it depends on several factors:

• Carrier — different Australian carriers have different international roaming arrangements.
• Roaming availability — your carrier needs to have a roaming agreement with an Indonesian network.
• Account settings — some plans may need roaming enabled at the account level.
• Device configuration — your phone's settings determine whether the Australian SIM can register on a roaming network.

Receiving and sending SMS while overseas may have different carrier terms compared to using SMS at home in Australia. SMS is not necessarily free while roaming.

The safest approach is to check your Australian carrier's current international roaming terms before you travel, so you know exactly what to expect for SMS usage in Bali.

What about bank verification codes and two-factor authentication?

Keeping your Australian SIM installed can be useful when services like your bank send verification codes to your Australian mobile number.

However, successful delivery of these SMS messages depends on your Australian carrier's roaming configuration and the service sending the code. Some services may not send SMS to numbers that are roaming internationally, and some carriers may not reliably deliver SMS while roaming.

We can't guarantee delivery of banking or authentication SMS while you're in Bali. If you rely on SMS verification for banking or other critical services, check with your carrier and consider alternative authentication methods (such as authenticator apps, which work over data) before you travel.

Will WhatsApp keep my Australian number?

Yes. WhatsApp is associated with the phone number used to register your account, not with the SIM providing your mobile data.

Changing your phone's mobile-data connection to a Bali travel eSIM does not normally require changing your WhatsApp number. Your contacts can still reach you on your usual WhatsApp number, and WhatsApp can use the Bali eSIM's internet connection for messages and calls.

WhatsApp is a third-party service, and Roamza doesn't control how it works. For more on using specific apps with a Bali eSIM, see our Bali apps guide.

Can I make and receive normal calls?

There's an important distinction between traditional carrier calls and internet-based calls:

• Traditional calls — using your Australian SIM to make or receive standard phone calls while in Bali remains subject to your Australian carrier's international roaming terms. Check your carrier's rates before you travel.
• Internet-based calls — apps like WhatsApp, FaceTime and Messenger can use your Bali eSIM's mobile data connection for calls, where supported by the app and your device.

If you plan to use traditional calls on your Australian SIM in Bali, check your carrier's roaming call rates first, as these can be significantly higher than domestic rates.

How do I stop my Australian SIM using roaming data?

If you want to keep your Australian SIM installed but don't want it using roaming data, here's the conceptual setup:

• Keep your Australian SIM installed if you want to receive calls and SMS on your Australian number.
• Select your Bali/travel eSIM as the Mobile Data line — this tells your phone to use the eSIM, not the Australian SIM, for data.
• Disable Data Roaming on your Australian SIM — if you don't want your Australian carrier to provide international roaming data, turn it off for that line.
• Review Mobile Data Switching — if your phone automatically switches between lines for data, consider turning that off so you stay in control.
• Follow your travel eSIM's instructions for its own Data Roaming setting — some travel eSIMs require Data Roaming enabled on the eSIM line to connect to their partner networks.

This last point is important: Data Roaming is a per-line setting. Turning it off on your Australian SIM doesn't turn it off on your travel eSIM, and vice versa. Some travel eSIMs actually need Data Roaming enabled on the eSIM line to work.

For a deeper guide on this topic, see our guide to avoiding roaming charges in Bali.

Recommended setup before flying to Bali

Getting set up at home means you can test everything works while you still have reliable Wi-Fi:

1. Confirm your phone supports eSIM/dual SIM — use our compatibility checker to check your model.
2. Purchase your Bali eSIM — browse Bali plans and choose one that suits your data needs.
3. Install the eSIM using reliable Wi-Fi — follow the installation instructions provided with your purchase. See our installation guide for more context.
4. Label the Australian SIM "Australia" — name your lines clearly so you can tell them apart at a glance.
5. Label the travel eSIM "Bali" — makes it obvious which line is which.
6. Select the Bali eSIM for mobile data — make sure your phone is set to use the eSIM for data, not the Australian SIM.
7. Review roaming settings on both lines — check Data Roaming for each line separately, as it's a per-line setting.
8. Check your Australian carrier's roaming terms — know what to expect for calls, SMS and voicemail before you fly.
9. Save your Roamza setup instructions — screenshot or email them to yourself so you can refer to them when you land.

What happens when I land in Bali?

Follow the activation instructions supplied with your selected eSIM. Activation conditions vary by product — some eSIMs connect automatically, others may require specific steps, so don't assume a universal setup.

Once your travel eSIM is connected and selected as your mobile data line, data-based apps like WhatsApp, Google Maps and Grab can use that connection. Your Australian SIM remains installed and available for calls and SMS, subject to your carrier's roaming terms.

For a step-by-step setup guide, see our Bali eSIM setup guide.

Australian SIM vs Bali eSIM: what does each one do?

Before you fly checklist

• ✓ Check eSIM compatibility
• ✓ Install before departure
• ✓ Keep Australian SIM installed if required
• ✓ Select Bali eSIM for mobile data
• ✓ Check roaming settings on BOTH lines
• ✓ Review Australian carrier roaming terms
• ✓ Save installation instructions

BUY BEFORE YOU FLY.

For more reading, see our Bali eSIM vs SIM Card guide or browse Bali eSIM plans.