Vietnam

An eSIM is a digital SIM that allows you to activate a mobile data plan without inserting a physical SIM card.

No. We provide data-only prepaid eSIM plans. Calls and SMS are not included.

You can make internet-based calls (WhatsApp, Telegram, Messenger, FaceTime, etc.), but you cannot make emergency or cellular calls (112/911) using an eSIM data-only plan.

Check your device settings or search “model + eSIM support” online. Most newer iPhones, Samsung, Google Pixel devices, and some tablets support eSIM.

Some devices are carrier-locked or only support eSIM in certain regions. Make sure your device is unlocked.

Yes, activation can be done before arrival - the plan starts when the eSIM connects to a supported network.

No, you can use both at the same time (dual SIM / dual standby).

Data Credits, which are displayed as Credits are your prepaid balance on saysim.io. Instead of entering payment details every time you buy an eSIM plan, you can add Credits to your account and use them whenever you need. One Data Credit always equals 1 EUR, and the balance stays in your account until you spend it.