Samsung S23 Dual SIM Settings for Travel Abroad

To use your Samsung Galaxy S23 with dual SIMs while traveling, you need to keep your home SIM active for calls and SMS while setting your AussieRoam eSIM as the primary source for mobile data. This configuration ensures you stay connected to local networks in places like Bali or Japan while still receiving important 2FA bank codes on your Australian or Kiwi number. By managing these settings correctly in your SIM Manager, you can completely avoid the $10 daily roaming charges from carriers like Telstra or Optus.

Why the Samsung S23 is a Travel Powerhouse

The Samsung Galaxy S23 series is arguably one of the best tools for an Australian or New Zealander heading overseas. Whether you are trekking through the humid streets of Bangkok or navigating the London Underground, the S23’s ability to handle a physical SIM and multiple eSIMs simultaneously is a game-changer. Most of us are used to the old way of doing things: landing in a new country, fumbling for a paperclip, and swapping out our home SIM for a local one, only to lose that tiny piece of plastic in a taxi. With the S23, those days are over. You can keep your Aussie or Kiwi SIM tucked safely inside the phone and simply layer a data-only eSIM on top.

Before you head to the airport, you should check if your phone is compatible with eSIM technology. Since you are rocking an S23, you are almost certainly good to go, provided your device isn't locked to a specific network provider. Most S23 units sold in Australia and NZ are unlocked, but it is always worth a quick check if you bought yours on a specific contract.

The Roaming Trap: Why Telstra and Optus Aren't Your Friends

We have all been there. You land in Denpasar or Narita, turn off airplane mode for a second to message home, and suddenly you get a text: "Welcome to Indonesia! Your International Day Pass has been activated. That will be $10, thanks." If you are away for three weeks, that is $210 gone before you have even bought your first Bintang.

Optus and Telstra make a killing on these daily fees. They claim it is for your convenience, but in reality, they are just reselling local data at a massive markup. By using an AussieRoam eSIM, you are bypassing these middlemen. Our eSIMs connect you directly to local carriers like Telkomsel in Indonesia (dest:as-20) or Softbank in Japan (dest:jp). You get local rates and local speeds without the "convenience fee" that home telcos love to tack on.

Step-by-Step: Configuring Your S23 Dual SIM Settings

Once you have grabbed your eSIM from AussieRoam, the setup is straightforward. We recommend doing the initial installation while you are still at the airport in Sydney, Melbourne, or Auckland using the free Wi-Fi. This way, the second you touch down, you are ready to roll. For a more detailed look at the process, check out our simple setup guide.

1. Access the SIM Manager

Go to Settings > Connections > SIM manager. This is the cockpit for your S23’s connectivity. You will see your physical SIM (your home number) and an option to "Add eSIM."

2. Add Your AussieRoam eSIM

Tap Add eSIM and scan the QR code provided in your AussieRoam confirmation email. Your phone will take a minute to register the new profile. Once it is added, give it a name like "Travel Data" or "AussieRoam" so you don't get confused.

3. Set Preferred SIMs

This is the most critical part of the process. Under the "Preferred SIMs" section, you will see options for Calls, Messages, and Mobile Data.

• Calls: Set this to your "Primary" (Home) SIM. This allows you to receive calls, but be careful—answering them might trigger roaming charges. Most travelers leave this on just to see who is calling.
• Messages: Set this to your "Primary" (Home) SIM. This is vital for receiving those 2FA codes from your bank or MyGov while you are abroad.
• Mobile Data: Set this to your AussieRoam eSIM. This ensures that every kilobyte of data used for Google Maps, Instagram, or WhatsApp comes out of your prepaid travel plan, not your expensive home plan.

4. Turn Off Data Switching

Scroll down to the bottom of the SIM manager page and ensure Data switching is turned OFF. If this is on, your S23 might try to use your home SIM for data if the eSIM signal gets weak, which is a one-way ticket to a huge phone bill.

Regional Realities: Coverage and Carriers

Knowing your settings is half the battle; knowing the local landscape is the other. Here is what you can expect when using your S23 in our most popular destinations.

Bali and Indonesia

In Bali, coverage is generally excellent in tourist hubs like Seminyak, Canggu, and Ubud. Our eSIMs typically hook into Telkomsel, which has the widest reach across the archipelago. If you are heading out to the Nusa Islands or the Gili Islands, you might see your signal drop to 4G or even 3G in remote spots, but the S23’s powerful antennas usually hang on well. If you are planning a longer stay, you might find our Best Coworking Spaces in Bali: A Digital Nomad’s Guide helpful for finding spots with the best Wi-Fi to supplement your mobile data.

Japan

Japan (dest:jp) is a dream for S23 users. The infrastructure is incredible. You will likely be connected to NTT Docomo or Softbank. Even in the deep underground subways of Tokyo or Osaka, you will usually have a solid 4G or 5G connection. If you are heading to the ski fields of Niseko or Hakuba, the coverage remains surprisingly strong. For more tips on saving money in the Land of the Rising Sun, read our guide on How to Travel Japan on a Budget: Tips for Australians.

Thailand

When you land at Suvarnabhumi Airport in Bangkok (dest:th), your S23 will likely pick up AIS or DTAC. These networks are incredibly fast. You will have no issues streaming video or using ride-hailing apps like Grab. Coverage in the islands like Koh Samui or Phuket is also very reliable, though it can get patchy if you are on a long-tail boat far from the shore.

UK and Europe

Traveling through the UK (dest:gb) and Europe (dest:eu-42) is where the dual SIM S23 really shines. Our Europe-wide eSIMs allow you to cross borders—say, from London to Paris to Amsterdam—without ever changing your settings. Your S23 will automatically hunt for the best local partner, whether it is Vodafone in the UK, Orange in France, or Movistar in Spain. For more on avoiding those pesky European roaming costs, see our article on Avoiding Hidden Roaming Fees in Europe: A Guide.

Comparison: AussieRoam vs. Home Carrier Roaming

Feature	Telstra/Optus Roaming	AussieRoam eSIM
Daily Cost	$5 - $10 per day	$0 (Prepaid upfront)
Data Allowance	Usually 1GB - 5GB per day	Large buckets (up to 20GB+)
Network	Roaming Partner (lower priority)	Local Networks (high priority)
Number	Keep your Aussie/Kiwi number	Data only (no local number)
Bill Shock	High risk	Zero risk

How Much Data Do You Actually Need?

Since AussieRoam plans are data-only, you won't get a local phone number. This means you will be relying on data for everything—WhatsApp calls, iMessage, Google Maps, and social media.

• Light User: If you are just using Google Maps and occasional messaging, 1GB to 3GB per week is plenty.
• Social Media Lover: If you are posting Reels or TikToks of your sunset dinners in Uluwatu, you will want at least 10GB for a two-week trip.
• The Navigator: Using Google Maps heavily for driving through the Scottish Highlands or the Japanese countryside can eat up data surprisingly fast because of the map tiles being downloaded. Aim for a 5GB+ plan.

Expert Tips for S23 Travelers

1. Download Offline Maps: Even with a great eSIM, there are dead zones. Download your maps on Google Maps while you are on hotel Wi-Fi to save data.
2. Disable Auto-Updates: Go into the Play Store settings and ensure apps only update over Wi-Fi. A single app update can chew through 500MB of your travel data in minutes.
3. Use WhatsApp for Everything: Since you don't have a local number, use WhatsApp, Messenger, or Signal for calls. They use very little data and the quality is often better than a roaming voice call.
4. Check Your Usage: On your S23, go to Settings > Connections > Data usage to see exactly how much your travel eSIM has consumed. It helps you pace yourself so you don't run out before the end of your trip.

If you are still deciding which plan is right for you, take a look at our breakdown of the Best eSIM for Australian Travelers: Top Picks for 2026 to see how various regions compare.

The bottom line

Setting up your Samsung S23 for dual SIM use is the smartest move you can make before heading overseas. By keeping your home SIM for messages and using an AussieRoam eSIM for data, you get the best of both worlds: staying connected to home while enjoying local speeds and prices. It takes less than five minutes to set up, and it will save you hundreds of dollars in roaming fees. Land like a local, skip the SIM card queues at the airport, and spend that saved money on another round of drinks or a better tour. Safe travels!