Plugs & voltage in Thailand
Types A, B, C and O · 220 V · 50 Hz
No other country of the 139 uses exactly this combination, Types A, B, C and O. The closest match is the Philippines (A/B/C). Type O (TIS 166-2549) is rare: Thailand is the only country that uses it. Sockets here take plugs from countries on the other voltage range, so a plug that fits is no sign the supply matches.
Do I need an adapter for Thailand?
Where are you travelling from?
Plugs fit, but the voltage is different.
220 V here, 120 V at home.
Bring an adapter to Types A, B, C or O.
Bring an adapter to Types A, B, C or O.
Type C plugs fit; Type E/F plugs need an adapter to Types A, B, C or O.
Bring an adapter to Types A, B, C or O.
Bring an adapter to Types A, B, C or O.
Type A plugs fit; Type I plugs need an adapter to Types A, B, C or O.
Bring an adapter to Types A, B, C or O.
Type C plugs fit; Types D and M plugs need an adapter to Types A, B, C or O.
Plugs fit, but the voltage is different.
220 V here, 100 V at home.
The power supply
Also in the data
How we checked it: Type O is Thailand's national earthed plug (TIS 166-2549). Wikidata does not list it, so it was added from technical references. Type F is not shown because only one of our two main sources lists it.
Four socket types are in use here; only 5 countries list more, and 7 others also list four.
Crossing into Malaysia means a different plug: no socket type matches.
Next door the nominal figure is 230 V in every case, against 220 V here.
The plug types used here
Guides: When the plug fits but the voltage doesn’t · Countries with several plug types, ranked
Source: Wikidata Q869, corrected against a cited source; regions: UN M49 (South-eastern Asia). Sources & method