Mains electricity by country includes a list of countries and territories, with the plugs, voltages and frequencies they use for providing electrical power to small appliances and some major appliances. Every country has differing rules regarding distribution of electricity for portable appliances and lighting. Voltage, frequency, and plug type vary widely, but large regions may use common standards. Physical compatibility of receptacles may not ensure compatibility of voltage, frequency, or connection to earth ground.
This article lists the plug type, voltage and frequency commonly expected for many territories. In some areas, older standards may still exist. Foreign enclaves or buildings frequented by tourists may support plugs not otherwise used in a country, for the convenience of travellers.
The International Electrotechnical Commission publishes a web microsite World Plugs which provides the main source for this page, except where other sources are indicated. World Plugs includes some history, a description of plug types, and a list of countries giving the type(s) used and the mains voltage and frequency.
Although useful for quick reference, especially for travellers, IEC World Plugs may not be regarded as totally accurate, as illustrated by the examples in the plugs section below, and errors may exist, such as Indonesia being listed as using both 220 V and 110 V when the Indonesian Standard SPLN 1 clearly states the voltage as 230 V.
A plug is defined in IEC 60050 as an accessory having pins designed to engage with the contacts of a socket-outlet, also incorporating means for the electrical connection and mechanical retention of flexible cables or cords; a plug does not contain components which modify the electrical output from the electrical input (except where a switch and/or fuse is provided as a means of disconnecting the output from input). Informally, power conversion devices with incorporated plug pins may be also called "plugs", but IEC 60050 refers to these as 'direct plug-in equipment' defined as equipment in which the mains plug forms an integral part of the equipment enclosure so that the equipment is supported by the mains socket-outlet. In this article, the term 'plug' is used in the sense defined by IEC 60050.
The types used in each country are set by national standards, some of which are listed in the IEC technical report TR 60083, Plugs and socket-outlets for domestic and similar general use standardized in member countries of IEC.