Samsung Galaxy S25 Vietnam eSIM Setup – Step by Step

The Samsung Galaxy S25 series (S25, S25+, S25 Ultra) all support eSIM natively. If you purchased an international model (unlocked or carrier-specific outside mainland China), you have the necessary hardware — no carrier lock prevents eSIM use. However, variants sold in mainland China, Hong Kong, and Macau do not include eSIM hardware at all. Always verify your device model before buying an eSIM; if you have one of those variants, you will need a physical SIM or a pocket Wi‑Fi instead.

You will need a stable Wi‑Fi connection to download and install the eSIM profile. Hotel Wi‑Fi, airport Wi‑Fi, or your home network before departure all work well. Purchase a Vietnam eSIM plan from simvietnam that matches your trip length — for example, a 7‑day Viettel plan is a solid choice for short visits. Keep your order confirmation email handy; the QR code inside is your key to activation.

Step 1: Buy your Vietnam eSIM online. After payment, you receive a QR code via email. Do not scan it yet unless you are connected to Wi‑Fi — the profile download requires an active internet connection. Step 2: Connect your Galaxy S25 to Wi‑Fi. Open Settings → Connections → SIM card manager → Add eSIM.

Step 3: Tap 'Scan QR code from service provider' and scan the QR code from your email. The profile will download and activate automatically. Step 4: After installation, return to SIM card manager. Label the eSIM something memorable like 'Vietnam Data', and if you want to keep your home number active, set your primary SIM for voice and SMS only. Step 5: Enable 'Mobile data' on the eSIM line and turn on data roaming (required for local network access). Then select the eSIM as the default data SIM.

Step 6: The phone will connect automatically to the local carrier — Viettel or Vinaphone depending on your plan. Activation usually completes within two minutes. No additional APN configuration is needed for most carriers; data works straight out of the box.

If the QR code fails to scan or download, ensure you are on Wi‑Fi and that the QR code hasn’t expired — codes are valid for 7 days after purchase. If it still fails, contact customer support with your order number. If you see no network after installation, toggle Airplane mode on and off, or restart the phone. Double‑check that data roaming is enabled specifically for the eSIM line.

Dual‑SIM conflicts can occur. The Galaxy S25 supports one physical SIM plus one eSIM, or two eSIMs if no physical SIM is inserted. Make sure the correct SIM is selected for data in SIM card manager. If the eSIM profile disappears, go to Settings → Connections → SIM card manager → eSIM and choose 'Download again' — profiles can be re‑downloaded within the validity period. If you get an 'unsupported device' error, your phone is likely a China/HK/Macau variant without eSIM hardware. In that case, use a physical SIM or a portable Wi‑Fi hotspot.

For Viettel plans: data roaming must be ON. The APN is usually set automatically to 'viettel.vn'. If you need to enter it manually, create a new APN with these fields: Name – Viettel, APN – viettel.vn, MCC – 452, MNC – 04. For Vinaphone plans: data roaming ON, APN should be 'm-wap' or 'vinaphone.vn'. Manual entry works if the automatic setting doesn’t take effect.

To keep your home number active while using the Vietnam eSIM, set the eSIM as the default for mobile data only. Leave your physical SIM or other eSIM for calls and SMS. Disable mobile data on the home line to avoid international roaming charges. If you prefer to lock your phone to one carrier for better coverage — for example, Viettel offers strong signals in rural areas — disable automatic network selection and pick your preferred network manually. The default setting is automatic, which works fine in most cities.