Phone service crossing borders, Vietnam>Thailand>Laos>Cambodia

Question

I'll be traveling to SE Asia, and want one phone service. If I buy a SIM card with Viettel in Vietnam, will it function in Thailand and in Laos and in Cambodia?

If it does, will I be charged roaming?

Answer 1

Yes and yes. There are no universal SIM cards in SE Asia, they all charge roaming fees, which can be quite expensive. It is much easier and more economical to get a pre-paid SIM card in each country as you travel. Or use voip services through your hotel's wifi each night.

Answer 2

As of 2017-01-11 Yes and partial yes.

There are no universal SIM cards in SE Asia.

However, from 2017-01-01, Viettel removed reduced roaming charge in Vietnam, Laos, Cambodia.

Source: http://vneconomictimes.com/article/business/viettel-to-scrap-mobile-roaming-charges

The new fee can be found here (unfortunately it's in Vietnamese) in tab "Cước Roaming Đông Dương".

The new fee is:

• 2000 VND/min (my normal charge is 1380 VND/min) for calling between Viettel, Metfone (Cambodia), Unitel (Laos),
• 7260 VND/min to call to other operators in the roaming country.
• 27500VND/min to call to other operators in the home country.
• 500 VND/sms (compare to normal 290/350 VND/sms) between Viettel, Metfone (Cambodia), Unitel (Laos)
• 4840 VND/sms to other operators.
• free to receive call/sms
• 2 VND/10KiB Data (the normal data charge inside Viet Nam is 75VND/50KiB if you don't buy an extra data package)

Answer 3

As of 2024 you can get an eSIM from Airalo or another virtual operator that covers all 4 countries for a reasonable price. Airalo currently lists an "Asia eSIM" where you get 5GB for $20, covering 14 countries in the region.

Disclaimer: I'm not affiliated with Airalo or eSimDB. I've used Airalo before but I'm not paid by them.

Answer 4

I have been using since 2013, thereabouts, SIM cards by China Unicom HK that are valid in a selection of countries. So answers around 2016 saying There are no universal SIM cards in SE Asia were already incorrect.

And today in 2024 it's even easier, with SIMs and eSIMs available from many providers.