Mobile phone
59% cheaper than in Philippines
You can buy a SIM card for about 34,014.15 VND (72.57 PHP), which includes 1 GB of data plan. You can choose from 4 telecoms: MobiFone, Vietnamobile, Viettel or Vinaphone.
Mobile phones
Vietnam uses similar GSM mobile networks (GSM 900 and GSM 1800) as Philippines so you should be able to normally use your mobile phone.
Roaming
If you don't want to buy SIM card in Vietnam upon arrival, make sure to check the roaming charges with your telecom provider before your departure so there are no surprises when you return home.