Galaxy S25 Dual SIM in Vietnam: Complete Guide for Travelers 2025

The Galaxy S25 dual SIM Vietnam capability is one of the most discussed features among international travelers. With the rise of eSIM technology, Samsung’s latest flagship allows users to combine a physical SIM and an eSIM—or even two eSIMs—depending on the variant. For those visiting Vietnam, knowing how to maximize this feature is essential to avoid roaming costs and enjoy high-speed local connectivity. This article provides practical guidance, case studies, and technical insights, linking back to the  guide on eSIM setup in Vietnam.

📌 Understanding Dual SIM Options on Galaxy S25

The Galaxy S25 series (S25, S25+, and S25 Ultra) supports multiple SIM configurations depending on the region:

• Physical SIM + eSIM: The most common configuration for unlocked global models.
• Dual eSIM: Available on European and Asian models, letting you run two eSIM profiles simultaneously.
• Single SIM locked versions: US carrier models (e.g., Verizon, AT&T) may restrict dual SIM functionality.

For travelers, having two active lines in Vietnam means you can keep your home number for OTP banking/SMS while using a local eSIM for cheap data.

🛠️ How to Enable Dual SIM on Galaxy S25 in Vietnam

1. Insert or add SIMs: Insert a physical SIM or scan an eSIM QR code (Settings → Connections → SIM manager → Add eSIM).
2. Label SIMs: Rename your SIMs (e.g., “Home” and “Vietnam Data”) for easier management.
3. Select default SIMs: Set one for calls/SMS and one for mobile data in SIM manager.
4. Enable Dual SIM always on: This feature ensures you don’t miss calls on either line, though it may use more battery.
5. Check APN: If data doesn’t work on the Vietnam eSIM, update APN (Viettel: v-internet, MobiFone: m-wap, Vinaphone: m3-world).

📊 Case Studies from 2025 Travelers

Case 1 – Business Traveler from France: A French consultant used Galaxy S25 Ultra with Orange eSIM (for OTPs) and a Viettel eSIM (5GB/day, $19.90). He reported seamless switching between networks during meetings in Hanoi, with 180 Mbps 5G speeds recorded using Speedtest.

Case 2 – Tourist from Singapore: A Singaporean couple traveling to Da Nang installed a MobiFone 20-day eSIM (4GB/day, $14.50) while keeping their Singtel physical SIM. They successfully used dual SIM mode for WhatsApp on the home number and high-speed streaming via MobiFone 5G.

Case 3 – Remote Worker from USA: A freelancer based in Ho Chi Minh City combined Google Fi (physical SIM) and Vinaphone eSIM (local). After configuring APN manually, both lines worked simultaneously, ensuring uninterrupted client communication and affordable local data.

⚡ Benefits of Using Dual SIM in Vietnam

• Cost savings: Avoid expensive roaming charges by using a local data eSIM.
• Flexibility: Keep your home SIM for SMS verification, while using Vietnam’s 4G/5G network for internet.
• Coverage: In rural destinations (e.g., Ha Giang, Ninh Binh), switching between Viettel and MobiFone ensures stable coverage.
• Productivity: Separate personal and work numbers without carrying two phones.

📶 Vietnam 4G/5G Performance on Galaxy S25

According to Ookla’s Q2 2025 data, Vietnam’s 5G average speed is 210 Mbps download. During field tests in July 2025, Galaxy S25 Ultra with Viettel 5G in Ho Chi Minh City recorded 220 Mbps download and 35 Mbps upload. In Da Nang, MobiFone 5G delivered 190 Mbps download.

⚠️ Common Issues with Dual SIM Setup

• “No Service” on second SIM: Check if both SIMs are enabled in SIM manager.
• Data not switching: Ensure “Allow mobile data switching” is turned on in SIM manager.
• eSIM missing option: Some US carrier models disable eSIM by default; only unlocked versions support it in Vietnam.
• Battery drain: Dual SIM always on may consume more power; disable if not needed.

🌐 Which eSIM Plans Work Best on Galaxy S25 Dual SIM?

Based on traveler needs in 2025, the following GoVnSIM eSIM plans are the most compatible with Galaxy S25 dual SIM:

• Viettel eSIM (5GB/day, 15 or 30 days, $14.90 – $19.90): Best for nationwide coverage, especially in rural provinces.
• Vietnam eSIM 30 Days – 6GB/day + free net calls (Ultimate Plan 2025) ($18.50): Runs on MobiFone network, includes a local VN number and unlimited in-app net calls.
• Vietnam eSIM 20 Days – 4GB/day (Best Plan 2025) ($14.50): Balanced option with phone number included, ideal for short-to-mid trips.
• Vietnam eSIM with Phone Number (3GB/day, 10 / 15 / 30 days, $8.50 – $13.50): Comes with a local VN number; the 15-day option includes 30 minutes of free calls.

For detailed device-specific instructions, see the: Device eSIM Setup Vietnam 2025 (iPhone, Samsung, Pixel, More).

Samsung’s official support also provides additional resources: Samsung Galaxy Support.

✅ Checklist Before Using Dual SIM in Vietnam

• Ensure your Galaxy S25 is unlocked.
• Update to the latest firmware (Android 15, August 2025 patch).
• Install both SIMs (physical or eSIM).
• Set preferred SIMs for calls, texts, and data.
• Save APN details for Viettel, MobiFone, Vinaphone.

📞 Need Help with Galaxy S25 Dual SIM in Vietnam?

If you encounter issues while setting up Galaxy S25 dual SIM in Vietnam, our team can assist with step-by-step troubleshooting and providing the right eSIM plans for your trip.

Contact: WhatsApp: +84 98 307 49 15 | LINE ID: anyaxiaoying | Email: info@govnsim.com