This page does not search a model list. A static catalog misses phones that shipped last month, and it treats one marketing name as one radio. That is how a mainland China iPhone gets marked as supported. The check is the phone you will travel with.

How to check the phone in your hand

  1. Dial *#06#. Write down whether an EID appears. That screen is the one we trust over a model name printed on a box.
  2. On iPhone, Settings, Cellular. The row Add eSIM or Add Cellular Plan means the software can see the hardware.
  3. On Samsung, Settings, Connections, SIM manager, and look for Add eSIM.
  4. On Pixel, Settings, Network and internet, SIMs, Download a SIM.
  5. Confirm the phone is not carrier-locked. A lock is a policy block, separate from the EID.

The exceptions that cause the angry emails

Apple has sold iPhone XS and later with eSIM in most countries. The mainland China range has for years been a dual nano-SIM phone without an eSIM, including generations that are eSIM-only in the United States. Hong Kong and Macau iPhones were often dual physical SIM on older models and gained eSIM on later ones. The same “iPhone 14” sentence is three different radios. Samsung does the same thing with Galaxy S and Z phones: a European S24 and a Hong Kong S24 are not guaranteed to match. Pixel 3 and later are the Google line with eSIM, sold unlocked more often, and still worth the *#06# check if the phone was imported.

Watches, most laptops, and Wi-Fi-only tablets are outside this product. A phone that only offers “add a physical SIM” after you have looked in the right menu is a no. Do not buy the QR and hope a software update invents an EID. Hardware does not arrive in an update.

If the phone shows an EID

Install on Wi-Fi before the flight, using the Get Started steps. Label the line Vietnam. Keep the home SIM for SMS. After landing, mobile data on the Vietnam line, data roaming off. The plan is 5GB high-speed per day for 7, 15, or 30 days at $9.99, $14.99, or $18.99. Compatibility is about whether the profile can live on the phone. Coverage is about Viettel’s network once it does. Those are different pages.

A model name is not a yes or a no. China and Hong Kong units can share a global name and still have no EID. Dial *#06#. If an EID is listed, the hardware can hold a profile. If you only see IMEI, do not pay. A photo of that screen is the right thing to send support before you buy.