What country has the highest voltage on their power outlets?

The majority of countries in the world run the residential AC mains in the vicinity

of 220, 230, or 240 volts.

The highest nominal supply is 240 volts AC, in all of the following countries:

Afghanistan

Brunei

Cook Islands

Cyprus

Falkland Islands

Fiji

Gibraltar

Guyana

Isle of Man

Kenya

Kiribati

Kuwait

Liberia

Malaysia

Nauru

Nigeria

Oman

Papua New Guinea

Qatar

St. Lucia

Seychelles

Tonga

Uganda

The UK