If you’re off to Thailand, you’ll soon clock that they use the Type O socket—a design that’s unique to the country.
This socket is tailored for a three-pronged, earthed plug featuring two round, parallel pins and a longer earth pin.
Features of the Type O Socket
Type O plugs are easy to spot with their round pins. They’re designed to fit snugly and safely into the sockets, ensuring a reliable connection every time.

Number of pins | 3 |
Grounded | Yes |
Voltage | 220 – 240 volts |
Ampere | 16 amps |
Other types of plugs that fit | Type C, E, and F (strongly discouraged!) |
Other socket compatible with Type F | None |
Do you need a travel adaptor for your UK devices? | Yes |
Type O sockets and plugs are rated for up to 16 amps and operate on a voltage range of 220 to 240 volts.
Click here if you need a travel adaptor for Type O
Dimensions
The power pins on a Type O socket have a diameter of 4.8 millimetres and are 19 millimetres long, while the earth pin extends to 21.4 millimetres.
The spacing between the power pins is also 19 millimetres, with the earth pin centrally aligned, 11.9 millimetres vertically from the line connecting the two power pins.
Using a Type O Plug
The Type O socket is exclusively designed for Type O plugs. While Type C, E, and F plugs might physically fit, using them can be hazardous and is strongly discouraged.
Type O sockets are unique to Thailand, although there is a variant that also accommodates Type A, B, and C plugs.
So, if Thailand is your destination, be aware that you’ll mainly find Type O sockets there. Unsure if your devices are compatible? It’s wise to use a suitable travel adaptor or check the specifics on this website using the search function (top right).
The Necessity of a Travel Adaptor
It’s definitely smart to bring along a travel adaptor that’s compatible with Type O sockets to sidestep any potential trouble.
Without the appropriate adaptor, you risk not being able to charge your devices, damaging your charger, or worse—causing short circuits, electrical shocks, or even fires. Best to be on the safe side!