Travel adapter from Vietnam to Tonga
Adapter Required
Yes — coming from Vietnam, you will need a travel adapter for Tonga. Vietnam uses Type A/Type B/Type C plugs, and Tonga uses Type I, so the pin shapes will not fit any wall socket.
Vietnam (home)
Type A
Two flat parallel pins
Type B
Two flat pins + round ground
Type C
Two round pins (Europlug)
Tonga (destination)
Electrical specs
Vietnam
230 V
50 Hz
= Match
Tonga
240 V
50 Hz
More about plugs in Tonga
In Tonga, the standard power plug is Type I. The country runs on 240 volts at 50 Hz. That means every wall socket in Tonga is the same shape — Type I, and your plug needs to physically match the socket to fit.